★ 4.9 / 5
from 881 verified reviews on G2, Capterra and Trustpilot
Kerio Migrator For Mail Server
When an organisation moves off Kerio Connect Mail Server, the migration touches every user mailbox: emails, contacts, calendars, tasks, notes, public folders. PCDOTS Kerio Converter Software reads the Kerio store, processes every user mailbox in one job, and lands the data at Office 365, Gmail, Exchange, Outlook PST, MBOX or any IMAP host. Mailbox Mapping covers admin-mode multi-user cutovers.
Kerio Connect organises every user mailbox under a per-user folder on the server, with messages stored as individual files plus contact, calendar and task data in companion stores. The PCDOTS wizard walks each user folder under the Kerio data store, parses the components, and writes the destination format - one user at a time or every user in bulk. Below: how the wizard handles the three phases of a Kerio cutover.
Phase One: Locate and Load the Kerio Mailbox Data
On a Windows machine running the Kerio Connect server, the wizard auto-detects the data store path under Control Panel > Mail > Advanced > Data Storage. Where the server runs on Linux or Mac, copy the data folder to a Windows machine and use the manual browse option. Either path, the wizard parses each per-user folder, surfaces the user list, and reports message counts.
Auto-detect: configured Kerio Connect server on Windows
Manual browse: data folder copied from a Linux or Mac Kerio host
Per-user mailbox enumeration with message and folder counts
Phase Two: Scope, Preview and Apply Filters
Pick which users to migrate (all, a department, a single account). Drill into folders to confirm contents - Inbox, Sent, Drafts, Public Folders, custom folders. Click any message for a three-mode preview. Apply filter rules across To, From, Cc, Bcc, Subject, Date range, Has-Attachment to scope the conversion to exactly what the destination needs.
User-level scoping: all, department-level, or single mailbox
Folder-level scoping: include or exclude Sent, Drafts, Public Folders
Filter rules across header fields, dates, attachments
Phase Three: Cut Over to the Destination
Pick destination: file format (PST per user or merged, MBOX, EML, MSG, NSF, OLM, PDF) or live destination (Office 365, Gmail, Yahoo, Exchange, IMAP). Cloud destinations open the OAuth or app-password flow. Mailbox Mapping routes each Kerio user to the matching destination mailbox in admin-mode Office 365 jobs. Conversion log captures per-message status.
Live destinations: Office 365, Gmail, Yahoo, Exchange, IMAP
Mailbox Mapping for admin-mode multi-user Office 365 cutover
Mailbox Mapping for Office 365 Cutover
Office 365 admin migrations need each Kerio user mailbox routed to the correct destination mailbox - automatic name matching often misbehaves when usernames differ across systems. Mailbox Mapping shows a side-by-side table where the operator confirms or overrides each Kerio-to-Office365 pairing before the cutover begins.
Kerio Contacts to vCard 2.1, 3.0 and 4.0
Address book formats vary by destination. Older systems prefer vCard 2.1; modern address books accept 3.0 or 4.0. The wizard exports Kerio contacts to any of the three vCard versions, plus CSV for spreadsheet processing. Photo, organisation, multiple email and phone fields, addresses and free-form notes all retained.
Calendars to ICS With Recurrence Retained
Kerio calendars include single events, recurring meeting series, all-day events and reminders. The wizard exports each calendar to iCalendar (ICS) with recurrence rules, exception dates, attendee lists and reminders preserved exactly as Kerio stored them. ICS files import into Outlook, Google Calendar, Apple Calendar and any RFC 5545-compliant calendar app.
Public Folders and Shared Mailboxes Carried Through
Kerio Connect installations frequently use Public Folders for shared inboxes, distribution lists, and team calendars; plus shared user mailboxes for role-based accounts. The wizard treats both as first-class migration targets - public folders map to PST shared folders or Office 365 Public Folders, shared mailboxes route through Mailbox Mapping the same as personal accounts.
IMAP-to-IMAP Direct Migration Mode
When the destination is another mail server (Dovecot, Cyrus, Exchange, MDaemon), the fastest path is IMAP-to-IMAP: read directly from the Kerio Connect IMAP service, write directly to the destination IMAP service. No PST or MBOX file written. Ideal for server-to-server cutovers.
Standalone Windows Wizard, No Kerio Install Required
The wizard runs as a standalone Windows utility with no requirement that Kerio Connect be installed locally. Operators copy the Kerio data folder from any Kerio host (Windows, Mac, Linux), point the wizard at the local copy, and run the conversion. .NET Framework 4.5 or later is the only runtime requirement.
15K+Kerio user mailboxes tested
17Output destinations supported
99.5%Kerio migration success rate
881Verified user reviews
Simple 3-Step Process
The Kerio Migration in Three Stages
A typical Kerio Connect migration moves through three high-level stages: locate the Kerio data and load every user, scope which users and folders to include, cut over to the destination. The eleven-step walkthrough later on this page covers Kerio-specific details: data store path, Mailbox Mapping configuration, IMAP-to-IMAP mode, and admin-credential setup for Office 365 cutovers.
01
1. Locate the Kerio Data Store
On a Windows-hosted Kerio Connect server the wizard auto-detects the configured data store. For Linux or Mac Kerio installations, copy the data folder to the Windows conversion machine and use the manual browse option. The user list appears in the navigation pane.
02
2. Scope Users, Folders and Filters
Tick which Kerio users to include; expand each to scope folders. Click any message for content, headers or raw preview. Apply filter rules across sender, recipient, subject, date range or attachment presence to narrow the run before any data crosses to the destination.
03
3. Cut Over to the Destination
Pick a destination - PST per user or merged, MBOX, EML, MSG, NSF, OLM, PDF for files; Office 365, Gmail, Yahoo, Exchange, IMAP for live destinations. Cloud destinations open the OAuth flow; admin-mode Office 365 surfaces the Mailbox Mapping table.
Software Compatibility
Kerio Connect Source and Migration Destinations
Source: Kerio Connect Mail Server data store from Windows, Mac, or Linux Kerio installations - covering Kerio Connect 7.x onward through current GFI KerioConnect releases. Destination: 17 output targets spanning email file formats (PST, MSG, EML, EMLX, MBOX, NSF, OLM), document formats (PDF, PDF/A, HTML, MHT, RTF, DOC, XPS, TXT, CSV), and live cloud or IMAP destinations (Office 365, Gmail, G Suite, Yahoo, iCloud, Exchange, Hosted Exchange, IMAP). Contacts to vCard 2.1/3.0/4.0 or CSV; calendars to ICS.
Input File Formats / Servers
Specialized and Tested Across Every Common Email Source
The Kerio converter for Windows reads the Kerio Connect Mail Server data store from auto-detected configured accounts or copied folders from Linux and Mac Kerio hosts. Whether the data sits in orphan files on a hard drive or behind an IMAP login, the converter handles it natively without needing the original software installed.
Browse the full list of input file Kerio Connect source data and the migration destinations the Kerio converter wizard reads and writes.
Email File Formats8 formats
Format
Full Name
Type
Description
PSTInput & Output
Personal Storage Table
Microsoft Outlook
Primary Outlook data file containing emails, contacts, calendar, tasks, and notes.
OSTInput
Offline Storage Table
Microsoft Outlook
Offline cached copy of Exchange mailbox data. Supports inaccessible or orphaned OST files.
MBOXInput & Output
Mailbox Format
Thunderbird, Apple Mail, Eudora
Universal text-based mailbox format used by dozens of email clients and servers (see IETF RFC 4155 specification).
EMLInput & Output
Email Message
Multiple clients
Individual RFC 822 email message files. Widely supported by Windows Mail, Outlook Express, and others.
MSGInput & Output
Outlook Message
Microsoft Outlook
Single Outlook email message in Compound Document File format. Preserves all metadata.
OFTInput
Outlook File Template
Microsoft Outlook
Outlook email template files. PCDOTS converts OFT templates to any supported format.
OLMInput
Outlook for Mac Archive
Mac Outlook
Native archive format for Outlook on macOS. Contains emails, contacts, and calendar data.
DBXInput
Outlook Express Mailbox
Outlook Express
Legacy email storage format used by Microsoft Outlook Express (discontinued in 2006).
Desktop Email Clients9 clients
Email Client
Platform
Storage Format
Conversion Support
Microsoft Outlook
Windows / Mac
PST, OST, OLM
Full: emails, contacts, calendar, tasks, notes, attachments
Mozilla Thunderbird
Windows / Mac / Linux
MBOX
Full: all folders, subfolders, attachments, filters
Mailbird
Windows
SQLite / MBOX
Full: all mailbox data including multiple accounts
eM Client
Windows / Mac
SQLite DB
Full: messages, contacts, calendar, attachments
Mailspring
Windows / Mac / Linux
SQLite / MBOX
Full: all email data and account configurations
Postbox
Windows / Mac
MBOX
Full: Thunderbird-compatible MBOX format
Windows Live Mail
Windows
EML + WLMX
Full: all message folders and account data
Eudora
Windows / Mac
MBX (MBOX variant)
Full: legacy Eudora mailbox files
IceWarp
Windows / Linux
Proprietary
Full: direct IceWarp server data export
Cloud & Webmail Services7 services
Service
Type
Direction
Auth Method
Gmail / Google Workspace
Cloud Webmail
Input & Output
OAuth 2.0 / App Password
Microsoft Office 365
Cloud Business
Input & Output
OAuth 2.0 / Modern Auth
Yahoo Mail
Cloud Webmail
Input & Output
App-specific Password
iCloud Mail
Cloud Webmail
Input & Output
App-specific Password
Hotmail / Outlook.com
Cloud Webmail
Input & Output
OAuth 2.0
Google Takeout
Export Archive
Input
Takeout ZIP / MBOX
Any IMAP Server
Universal Protocol
Input & Output
IMAP / SSL / TLS
Email Servers5 servers
Server
Type
Storage Format
Notes
Zimbra
Open Source Server
Zimbra TGZ
Supports Zimbra Community & Enterprise editions
MDaemon
Windows Mail Server
MDaemon MAI
Direct MDaemon user folder access, no export needed
Kerio Connect
Business Mail Server
Kerio IMAP Store
Converts Kerio data stores directly without server access
Communigate Pro
Enterprise Server
Communigate CGP
Supports all Communigate mailbox folder structures
Lotus Notes / HCL
IBM/HCL Platform
NSF
Via intermediary conversion. Contact support for enterprise plans.
Output Destinations13 outputs
Output Format
Category
Best Used For
PST
Email File
Importing into Microsoft Outlook on any Windows PC
MBOX
Email File
Thunderbird, Apple Mail, Postbox, or any MBOX-compatible client
EML
Email File
Windows Mail, individual email archiving, or web uploads
MSG
Email File
Saving individual Outlook messages with full metadata
PDF
Document
Legal archiving, compliance, sharing non-editable email records
HTML
Document
Web-based email viewing, readable in any browser
CSV
Spreadsheet
Extracting email data for analysis in Excel or Google Sheets
vCard (VCF)
Contacts
Exporting contacts to any address book or CRM
ICS
Calendar
Exporting calendar events to Google Calendar, Apple Calendar
TXT
Plain Text
Simple archiving, text analysis, or importing into databases
Gmail
Cloud Service
Direct migration. Emails appear in Gmail inbox immediately
Office 365
Cloud Service
Direct migration to Microsoft 365 business mailboxes
IMAP Server
Protocol
Any IMAP-compatible server: Dovecot, Postfix, Exchange, etc.
Advanced Filters
What the Kerio Migrator Handles Beyond Mail
Mail conversion is only one strand of a Kerio Connect cutover. A complete migration also has to surface contacts, calendars, tasks, notes, public folders and shared mailboxes, plus give the operator a way to confirm what will move before any data crosses to the destination. The wizard treats each of these as first-class outputs running alongside the mail conversion.
Inspection is built into the wizard rather than locked behind a separate tool. The preview pane offers content view (rendered body the way Kerio Connect displayed it), headers view (every RFC 5322 field including Kerio-added X-* extensions) and raw view (unparsed bytes from the Kerio store). For inspection without conversion, see the Email Forensics Investigation tool.
Advanced search returns matches across thousands of folders in a fraction of a second. Search by sender, recipient, subject, date, attachment name, message body or any combination of these fields, and export the matching set as a separate output.
PCDOTS Kerio Converter v3.4
Smart Search
Why Users Switch to PCDOTS
Five Kerio Migration Problems and Their Fixes
Five recurring problems Kerio Connect administrators run into during a migration project. Each maps to a specific resolution in the PCDOTS wizard. Skip ahead to whichever situation matches the immediate blocker.
Problems You're Facing
Office 365 cutover with hundreds of Kerio user mailboxesA typical mid-size organisation moving from Kerio Connect to Microsoft 365 has 50 to 500 user mailboxes plus public folders plus shared accounts. Per-user manual export is impossible at that scale. The wizard processes the entire Kerio data store in one job, with Mailbox Mapping handling the Kerio-user-to-Office-365-mailbox routing decisions before the cutover starts.
Contacts, calendars and tasks stuck in the Kerio storeKerio Connect holds contacts, calendars and tasks alongside mail in the per-user data folder. Many migration tools handle only mail and force operators to find a separate solution for the rest. PCDOTS treats all four as parallel outputs from the same Kerio data load - vCard or CSV for contacts, ICS for calendars, native destination format for tasks.
Public folders missing from competing Kerio migration toolsKerio Public Folders frequently hold critical shared content - distribution lists, team calendars, departmental archives. Tools that focus on personal mailboxes skip Public Folders entirely, leaving operators to reconstruct the shared content manually on the destination. PCDOTS surfaces Public Folders on the same user list with their own routing options.
Kerio server runs on Linux or Mac, conversion runs on WindowsKerio Connect is multi-platform but the conversion wizard is Windows-only. The path forward: copy the Kerio data folder from the Linux or Mac host to a Windows machine via SFTP, network share, or external drive, then point the wizard at the local copy. Kerio data layout is identical across platforms; the wizard reads it the same way.
GFI acquisition aftermath - leaving Kerio for a different platformFollowing the 2017 GFI Software acquisition, many Kerio Connect customers have evaluated alternatives. Migration projects that start "we need to leave Kerio Connect" rarely come with a clear single destination - some users want Office 365, some want Gmail, some need PST archives, and the operator needs a tool that handles all three from the same Kerio source.
How PCDOTS Fixes It
One job covers every Kerio user mailboxAim PCDOTS at the Kerio data store and pick a destination. The wizard processes every user in one pass, applies Mailbox Mapping for cloud destinations, surfaces Public Folders alongside personal mailboxes, and writes a TXT-format conversion log per message. No size cap, no message-count cap, no per-user runs.
Mail, contacts, calendars and tasks all migrate togetherEach Kerio user data folder yields four parallel outputs: mail to PST/MBOX/EML/MSG/PDF, contacts to vCard 2.1/3.0/4.0 or CSV, calendars to ICS with recurrence and reminders intact, tasks and notes to the destination format. Operators no longer juggle multiple tools for one cutover.
Direct MBOX to Gmail migration in a single click.Connect your Gmail account inside the converter. PCDOTS pushes the messages straight into your inbox without a download and re-upload step.
Multiple destinations supported from one Kerio sourceA migration where some users go to Office 365, some get a PST archive, and some land at a different mail server gets handled as separate runs against the same Kerio data store - no need to re-extract for each destination. Wizard maintains the source state across runs.
Cross-platform Kerio hosts handled via folder copyLinux and Mac Kerio Connect installations work the same way as Windows ones: copy the data folder to a Windows conversion machine. The wizard parses Kerio data store layout uniformly across platforms - no platform-specific conversion required, no risk of data corruption from format mismatches.
Real-World Applications
Six Common Kerio Connect Migration Scenarios
After GFI Software acquired Kerio Technologies in 2017, organisations have steadily moved off Kerio Connect for a mix of cost, feature and platform-strategy reasons. Six recurring scenarios cover most of those migrations. Each maps to the same Kerio-data-load pattern, with destination changing per case.
Kerio Connect to Office 365 Admin Migration
The most common Kerio cutover: full organisation moving from on-premise Kerio Connect to Microsoft 365. Provide tenant admin credentials; the wizard enumerates Kerio users, surfaces the Mailbox Mapping table for confirming each user-to-mailbox pairing, then cuts over emails, contacts, calendars and tasks per user.
PST to Office 365Exchange migration
Kerio Connect to Outlook PST Per User
Smaller organisations or staged migrations want a per-user PST each employee imports into Outlook themselves. The wizard writes one PST per Kerio user mailbox; operators distribute the files via network share or USB drive. Each employee runs Outlook File > Open & Open Outlook Data File.
PDF exportGDPR compliance
Kerio Connect to Gmail or Google Workspace
Organisations adopting Google Workspace need every Kerio user mailbox in the destination Gmail account. The wizard authenticates via OAuth, streams Kerio messages directly into the Gmail mailbox, recreates Kerio folders as Gmail labels, and migrates contacts to Google Contacts via vCard import alongside the mail run.
Corrupted PSTForensic recovery
Kerio Connect to Another Mail Server via IMAP
Server-to-server cutovers (Kerio to Dovecot, Cyrus, MDaemon, Exchange) skip file output. The wizard reads the Kerio store and writes via IMAP to the destination server, recreating folder hierarchy. No intermediate PST or MBOX file needed; useful when both sides stay live during the transition.
MBOX to PSTEML to MSG
Kerio Connect to PDF/A for Compliance Archive
Mailbox data needed in a courtroom, audit binder, or long-term compliance archive converts to PDF or PDF/A. The wizard renders each message with body, inline images, attachment list, and Bates numbering on each page. PDF/A meets ISO 19005-1 for archives that must remain readable for years.
HIPAAHealthcare archives
Kerio Connect Decommissioning Backup
Kerio Connect being shut down but historical mailboxes need a portable archive. The wizard exports each user mailbox to MBOX (one file per folder) or per-user PST. Files open in Thunderbird, Apple Mail or Outlook without any Kerio dependency, and remain accessible long after the Kerio server is gone.
Contact extractionCRM enrichment
Why Customers Choose This Tool
Eight Reasons This Beats Other Kerio Migrators
The eight differentiators below separate PCDOTS Kerio Converter Software from the cluster, refined across 15,000+ tested Kerio user mailboxes spanning Kerio Connect 7 through current GFI KerioConnect releases.
Mailbox Mapping for Real Office 365 Cutovers
Auto-name-matching breaks the moment Kerio usernames diverge from Office 365 UPNs. The Mailbox Mapping table presents Kerio users alongside destination mailboxes, lets the operator confirm or override every pairing, and only starts the cutover once the mapping is approved. Other Kerio tools either skip this step or implement it incompletely.
Mail Plus Contacts Plus Calendars Plus Tasks
A complete Kerio Connect cutover involves more than mail. Many competing tools handle messages and ignore the rest, leaving operators to run two or three separate jobs for contacts, calendars and tasks. PCDOTS surfaces all of them as parallel outputs from one Kerio data load, with vCard 2.1/3.0/4.0 for contacts, ICS for calendars, native task formats for the destination.
Public Folders and Shared Mailboxes Treated as First-Class
Kerio Public Folders and shared role-based mailboxes are easy for migration tools to overlook because they live outside personal user accounts. The wizard surfaces them on the same user list, supports per-folder or per-mailbox routing, and lets operators choose whether shared content lands as Office 365 Public Folders, shared destination mailboxes or merged into a designated user PST.
IMAP-to-IMAP for Server-to-Server Cutovers
When the destination is another mail server rather than a cloud or file format, IMAP-to-IMAP avoids writing intermediate files entirely. The wizard reads from the Kerio Connect IMAP service and writes to the destination IMAP service in a single live operation, with folder hierarchy recreating on the new server.
Auto-Detect Plus Manual Browse for Cross-Platform Kerio Hosts
Kerio Connect runs on Windows, Mac and Linux servers; the wizard runs on Windows. Auto-detect handles Windows-hosted Kerio installations directly. For Mac and Linux Kerio hosts, the operator copies the data folder to a Windows machine and uses manual browse - same downstream behaviour, no platform conversion involved.
Three-Mode Preview Before Anything Crosses
Each Kerio message renders in three layers before any conversion runs: content (rendered body the way Kerio Connect displayed it), headers (every RFC 5322 field including Kerio-added X-* extensions), raw (unparsed bytes from the Kerio store). Useful for diagnostic review during the migration plan and for forensic chain-of-custody where required.
Vintage Kerio Releases Through Current GFI KerioConnect
Source coverage spans Kerio Connect 7.x onward, including the post-2017 GFI Software releases now branded as GFI KerioConnect. Older Kerio Mail Server installations from versions before the Kerio Connect rename also read identically; the wizard recognises legacy data store layouts as well as current conventions.
Bulk Operation Without Per-User Limits
Multi-user Kerio installations frequently run hundreds or thousands of mailboxes. The wizard handles them in one job rather than requiring per-user runs. No size cap, no message-count cap, no batch ceiling in the licensed edition. Conversion log records exact per-message status across the entire batch.
Technical Specs
System and Software Requirements
What you need to run the Kerio converter for Windows, plus the trial limitations.
Software Name
PCDOTS Kerio Converter
Current Version
3.4
Processor
Pentium-class or higher
RAM
Minimum 2 GB
Hard Drive Space
100 MB free space
Operating System
Windows 11, 10, 8.1, 8, 7, Vista, XP. Server 2019, 2016, 2012, 2008, 2003 and earlier.
Trial limitation: the demo edition exports up to 10 emails per folder so you can verify accuracy on real data before purchasing. The full edition has no limits and ships with a lifetime license.
Trial vs Full
Trial vs Licensed Edition for Kerio Migration
Both editions ship the same binary, the same Kerio data store auto-detect, the same 17-target output catalog, the same Mailbox Mapping feature for Office 365 admin migrations. The trial caps writer output at 25 messages per Kerio folder. The licensed edition ($99 one-time, single-workstation, perpetual) removes the cap, adds priority Kerio-specialist support, and ships lifetime updates as Kerio Connect and GFI KerioConnect releases evolve.
How PCDOTS Kerio Converter Compares to Alternatives
Kerio Connect migration options split into three groups: dedicated Kerio commercial wizards that auto-detect the Kerio data store and process every user mailbox in bulk, generic email converters that recognise Kerio only as one of many sources and miss the Mailbox Mapping shortcut, and manual IMAP-to-IMAP scripts (imapsync, custom shell scripts) that require Linux expertise and skip non-mail components like contacts, calendars and tasks. Key PCDOTS differentiators: Mailbox Mapping for Office 365 admin migrations, mail-plus-contacts-plus-calendars-plus-tasks in one job, public folders treated as first-class, IMAP-to-IMAP available alongside file output.
Feature
Best ChoicePCDOTS
Other Paid ToolsAid4Mail, Stellar, etc.
Free Tools / Online
Kerio Auto-Detect Plus Manual Browse
25+
10 to 40+
2 to 5
Standalone, No Kerio App Required
Yes
Partial
No
Bulk Multi-User Kerio Migration in One Job
Yes
Yes
No
Mailbox Mapping for Office 365 Admin Migrations
Yes
Partial
No
Three-Mode Kerio Preview Pane
Yes
Partial
No
Headers and Raw Message View
Yes
Partial
No
User, Folder, Date, Sender, Attachment Filters
Yes
Limited
No
Mail Plus Contacts Plus Calendars Plus Tasks
Yes
Partial
No
Free Trial Available
Yes
Yes
Yes
Lifetime License
Yes
No
N/A
Public Folders and Shared Mailboxes Handled
Yes
Varies
No
Kerio-Specialist Engineer Support
Yes
Limited
No
30-Day Refund Policy
Yes
Varies
N/A
Starting Price
$99
$49 to $149+
Free (limited)
Comparison based on publicly available Kerio Connect migration tool documentation at the time of writing. Capabilities may vary by competitor version. PCDOTS Kerio Converter Software is independently verified by 881 user reviews on G2, Capterra and Trustpilot.
Video Tutorial
Watch How to Convert Emails in 5 Minutes
A short walkthrough showing every step of the conversion workflow on a real source mailbox, from launch to verified output.
5 min walkthrough
YouTube
Real Performance Numbers
Kerio Migration Performance Reference
Performance numbers below come from two reference sources. Internal regression testing: 15,000+ Kerio user mailboxes spanning Kerio Connect 7.x through current GFI KerioConnect releases, with single-user to 500-user installations, with and without public folders, against a range of destination types (PST, Office 365, Gmail, IMAP). Customer survey data: 881 verified reviewers reporting on production Kerio Connect migration outcomes.
85%
Customer Satisfaction
93%
Output Accuracy
99%
Successful Test Runs
How It Works
Eleven-Step Kerio Migration Walkthrough
Standard eleven-step procedure for migrating Kerio Connect Mail Server data to any of the 17 supported destinations, deeper than the three-stage quick guide above. Each step references the corresponding wizard dialog and screenshot. Operator time per Kerio data store: 15-60 minutes depending on user count, message volume, and destination type.
Run the wizard from the Start menu or desktop shortcut on the Windows machine. The source selection dialog opens. Kerio Connect itself does not need to be running; the wizard reads the data store as a passive consumer.
Locate the Kerio Connect Data Store
On a Windows-hosted Kerio Connect server, click Open Configured Kerio Account and the wizard auto-detects the data store path. For Linux or Mac Kerio hosts, copy the Kerio data folder to the Windows machine first, then click Choose Folder and browse to the local copy.
View All Kerio Users and Mailboxes
The navigation pane lists every user mailbox on the Kerio Connect server with email address, message count and total size. Public folders and shared mailboxes appear alongside personal accounts. Each user expands to show Inbox, Sent, Drafts, Public Folders, Calendars, Contacts, Tasks, Notes with item counts.
Preview Each Kerio Message Before Conversion
Click any message in the navigation pane to render it in the preview pane. Content view shows the rendered HTML body the way Kerio Connect displayed it. Headers view exposes the full RFC 5322 header set including Kerio-added X-* extensions. Raw view shows the unparsed bytes from the Kerio store.
Apply Filter Rules to Scope the Migration
For batch jobs targeting a subset, apply filters: user selection, folder selection, date range, has-attachments toggle, sender domain match, subject keyword match. The filtered set forms the migration job. Useful when only a department or date range needs to cross.
Configure Auxiliary Outputs
Toggle which non-mail components export alongside mail: contacts to vCard 2.1/3.0/4.0 or CSV, calendars to ICS with recurrence, tasks and notes to native destination format, public folders as separate output, signatures per user mailbox.
Pick the Migration Destination
Three categories. Email file formats: PST (per user or merged), MBOX, EML, MSG, EMLX, NSF, OLM. Document formats: PDF, PDF/A, HTML, MHT, RTF, DOC, XPS, TXT, CSV. Live destinations: Office 365, Gmail, Yahoo, iCloud, Exchange, IMAP, Hosted Exchange, G Suite.
Configure Routing, Mailbox Mapping and Credentials
Per-user routing: one merged file vs one per Kerio user. Naming patterns: Subject, Date, From plus Subject. For Office 365 admin migrations, complete the Mailbox Mapping table to confirm Kerio-user-to-Office365-mailbox pairings. For Gmail and IMAP destinations, complete OAuth or app-password authentication.
Execute the Migration Job
Click Save. The wizard processes Kerio users sequentially. Per-user progress shows: user name, email count, attachments extracted, contacts exported, calendar items written, output destination status. The TXT-format conversion log records exact per-message and per-user outcomes for audit trails.
Confirm the Migration Result
When the wizard reports Job Complete, the destination contains the migrated data. The trial edition caps the writer at 25 messages per Kerio folder; the licensed wizard processes any size data store without limits. Click Open Folder for file outputs, or open the destination cloud account for live-send destinations.
Validate Mailboxes in the Destination System
Open destination mailboxes in their native client: PST imported into Outlook, MBOX dropped into Thunderbird Local Folders, Office 365 mailboxes via Outlook on the web, Gmail via the Gmail web interface. Spot-check that Kerio folder hierarchy, contacts, calendars, tasks and public folders all crossed correctly. Compare per-user item counts against the wizard's conversion log.
Independent Validation
Reviewed and Awarded by Trusted Software Sites
Independent third-party verification of PCDOTS Kerio Converter against documented Kerio Connect migration capabilities. Each award sources from the original publisher (Software Informer, Softpedia, Soft32, FileHippo). The aggregate rating combines 881 verified reviewer responses since the most recent major release.
4.6
Average across all reviews
1,408
Verified user reviews
4
Editor's Choice awards
Editor's Pick
5.0
Software Informer
"100% Clean Award for error-free and virus-free email conversion across formats and sources."
100% Clean Award
5-Star Rated
5.0
Softpedia
"Earns a 5-star rating for ease of operation and smooth email conversion."
100% Free Award
Top Rated
4.5
Soft32
"4.5 stars: an all-in-one solution for converting email files to multiple output formats."
Editor's Review
Verified Safe
5.0
FileHippo
"100% Clean Award for secure and safe email conversion."
Safety Verified
100% authentic. Every award above is verified directly from the issuing publisher's site. PCDOTS does not pay for placement, reviews or ratings.
Quick Definition
What Is a Kerio Connect Migration Tool?
A Kerio Connect migration tool reads the Kerio Connect Mail Server data store and converts each user mailbox - emails, contacts, calendars, tasks, notes, public folders - to standard email file formats (PST, MBOX, EML, MSG, PDF) or to direct cloud destinations (Office 365, Gmail, Yahoo, IMAP). The PCDOTS Kerio Converter Software auto-detects the configured Kerio data store on Windows-hosted servers, supports manual folder browse for Linux and Mac Kerio hosts, processes every user mailbox in one bulk job, and ships Mailbox Mapping for admin-mode Office 365 multi-user migrations.
Quick Verdict
Best for: Bulk Kerio Connect Mail Server migration on Windows for IT teams cutting over to Office 365, Gmail, Exchange, Outlook PST or any IMAP host - including contacts, calendars and public folders.
Free trial: 25 messages per Kerio folder, no credit card, lifetime trial.
Price: $99 one-time payment for a lifetime license.
Platforms: Windows 11, 10, 8, 7, Vista, XP plus all Server editions.
Rating: 4.9 out of 5 from 881 verified reviews on G2, Capterra and Trustpilot.
Privacy: 100% local processing, GDPR-compliant, no data uploaded to PCDOTS servers.
FAQs
Kerio Migration Reference Questions
Twelve reference questions covering Kerio Connect migration: what is Kerio Connect Mail Server and version coverage, public folders handling, conversion to PST/MBOX, contacts to vCard, calendars to ICS, Mailbox Mapping for Office 365, Gmail and IMAP destinations, dependency requirements, and trial limits. Sourced from real Kerio administrator search queries.
Does the wizard handle Kerio Public Folders and shared mailboxes?
Yes. Public Folders appear on the user list as standalone migration targets and route to Office 365 Public Folders, PST shared folders, or merged into a designated user PST. Shared mailboxes (role-based accounts, distribution-list inboxes) route through Mailbox Mapping the same way personal accounts do.
What is Kerio Connect Mail Server and where is the data stored?
Kerio Connect Mail Server is an enterprise messaging and collaboration platform that handles email, calendars, contacts, tasks, notes, and instant messaging. Originally from Kerio Technologies, it was acquired by GFI Software in 2017 and now ships as GFI KerioConnect. Server data lives in a per-user folder structure under the configured data store path (visible in the Kerio admin interface at Configuration > Server Settings > Store Directory). Each user folder contains messages, contacts, calendars and tasks alongside server metadata.
How do I convert Kerio Connect mailboxes to Outlook PST?
Open the wizard. The Kerio data store auto-detects on Windows machines hosting Kerio Connect; if the Kerio server runs on Linux or Mac, copy the data folder to the Windows machine first and use Choose Folder. The wizard lists every Kerio user. Tick which users to migrate, click any message for content/headers/raw preview, then click Export and select PST. Configure routing - one merged PST or one per Kerio user mailbox - and click Save. Each generated PST imports into Outlook through File > Open & Open Outlook Data File. Folder hierarchy, contacts, calendars and tasks all carry through.
Can I convert Kerio Connect mailboxes to MBOX?
Yes. Pick MBOX as the destination and the wizard writes one .mbox file per Kerio folder by default, or one merged .mbox per user. Drop the resulting files into the destination Thunderbird profile under Local Folders, or use Apple Mail's File > Import Mailboxes. Both clients pick the data up on the next launch.
How do I export Kerio contacts to vCard?
Toggle the contacts export option alongside the main mail conversion or run it as a standalone job. The wizard reads the Kerio address book and writes vCard 2.1, 3.0 or 4.0 based on operator selection - older systems prefer 2.1, modern address books accept 3.0 or 4.0. CSV is the alternative when destination needs a spreadsheet. Photo, organisation, multiple emails and phones, addresses and notes all retain.
How do I export Kerio calendars to ICS?
Toggle the calendars export option. The wizard reads each Kerio user's calendar store and writes an iCalendar (ICS) file per user. Recurrence rules for repeating meetings, exception dates for cancelled or rescheduled occurrences, attendee lists, and reminders all retain. The resulting ICS files import into Outlook, Google Calendar, Apple Calendar and any RFC 5545-compliant calendar application.
Which Kerio Connect versions does the wizard support?
Source coverage spans Kerio Connect 7.x onward, including all post-2017 GFI Software releases now branded as GFI KerioConnect. The wizard recognises legacy Kerio Mail Server data store layouts as well as current conventions. Tested across Kerio Connect 7, 8, 9 and current GFI KerioConnect builds. Older Kerio MailServer installations from before the Kerio Connect rebrand also read identically.
How does Mailbox Mapping work for Office 365 admin migrations?
Office 365 admin migrations need each Kerio user routed to the matching destination mailbox. Auto-name-matching breaks when usernames differ (e.g., Kerio user jsmith maps to Office 365 [email protected]). The wizard surfaces a Mailbox Mapping table after Office 365 admin authentication: every Kerio user appears in the left column, every Office 365 mailbox in the right column, with proposed pairings highlighted. The operator confirms or overrides each row before the cutover starts. Bulk-fill from CSV available for large tenants. The cutover only begins once the mapping is approved.
Can I migrate Kerio Connect directly to Gmail?
Yes. Pick Gmail from the export menu and the wizard prompts for OAuth consent against the destination Google account. On consent, Kerio messages stream directly into the Gmail mailbox. Kerio folders translate to Gmail labels, attachments upload alongside each message, read/unread state and starred flags transfer. For Google Workspace tenants, admin-mode authentication enables bulk multi-user migration.
Can I run an IMAP-to-IMAP server-to-server migration?
Yes. Select IMAP as the destination, provide source Kerio Connect IMAP credentials and destination IMAP server hostname, port, encryption and credentials. The wizard reads from Kerio Connect via IMAP and writes to the destination via IMAP in one live operation, with folder hierarchy recreating on the new server. No intermediate PST or MBOX file written. Compatible with Dovecot, Cyrus, Exchange, MDaemon and any RFC 3501 server.
Do I need Kerio Connect installed on the conversion machine?
No. The wizard runs as a standalone Windows utility with no requirement that Kerio Connect be installed locally. For Kerio servers hosted on Linux or Mac, copy the Kerio data folder to the Windows machine and use the manual browse option. .NET Framework 4.5 or later is the only runtime requirement.
What does the free trial convert and how is it limited?
Trial caps writer output at 25 messages per Kerio folder. Loading any size Kerio data store, scoping which users and folders to process, browsing the preview pane, applying filters, configuring Mailbox Mapping all run unrestricted. The cap exists so operators can verify their actual Kerio data parses correctly before licensing. Licensed edition is $99 one-time, perpetual, single-workstation, lifetime updates and Kerio-specialist support included.
Customer Stories
Kerio Migration Reports From Production
Three production Kerio Connect migration reports below: 240-user organisation cutover from Kerio Connect to Microsoft 365 with Mailbox Mapping bulk-fill, Linux-hosted Kerio Connect 8 to per-user Outlook PST via folder copy, and Kerio Public Folders plus shared calendars migration with ICS recurrence retention. Reviewer identities verified by hosting platforms (G2, Capterra, Trustpilot).
G2 Reviews
4.7
412 reviews
Capterra
4.6
287 reviews
Trustpilot
4.6
521 reviews
Software Suggest
4.5
188 reviews
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"Migrated 240 Kerio Connect users to Office 365 in one job."
A 240-user organisation moving off Kerio Connect to Microsoft 365 over a single weekend. Mailbox Mapping was the feature that made this manageable - we had a CSV of Kerio username to Office 365 UPN mappings prepared in advance, the wizard accepted the bulk-fill, and after a quick eyeball confirmation the cutover started. Mail, contacts, calendars and public folders all crossed in the same job. Per-user conversion log made the post-migration audit straightforward.
EML to PSTFolder hierarchy preservedBulk conversion
GF
Genelia FernandesMigration Project Lead · California, United States
Verified review · G2
Cut a Linux Kerio host over to Outlook PST
Inherited a Kerio Connect 8 server running on Ubuntu and a stack of users who needed to keep their mail in Outlook on Windows. Other tools I tried only worked when Kerio was installed on Windows. Copied the data folder over via SFTP, pointed PCDOTS at the local copy, and per-user PST output worked first try. Each user imported through Outlook with one click.
Linux Kerio to Windows PSTManual folder browse mode
KJ
Kylie JohnSysadmin · Sydney, Australia
Verified · Capterra
Public folders and shared calendars all crossed
Our Kerio Connect deployment leaned heavily on Public Folders for shared inboxes and team calendars. Most Kerio migration tools I evaluated either skipped Public Folders entirely or treated them as an afterthought. PCDOTS surfaced them on the same user list as personal mailboxes, with their own routing options. ICS export retained recurrence rules on the team calendars, which several other tools dropped.
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Convert Kerio Connect Mailboxes Trial Edition, No Card Required.
Download PCDOTS Kerio Converter, convert up to 25 messages per folder and verify the wizard handles your exact Kerio Connect data store structure. Upgrade only when you are satisfied with the result.
