Written by Jennifer Walsh. Reviewed for technical accuracy by Shubham Dixit, Independent Expert in Email Forensics and Data File Conversion.
Shubham is an independent external reviewer and not an employee of PCDOTS.
Quick answer. Office 365 is now called Microsoft 365, and moving Yahoo into it is a mailbox-to-mailbox IMAP job. For an organization, Microsoft 365’s own admin center has a built-in IMAP migration. For a single mailbox, add both accounts to Outlook and drag, or use a tool. Yahoo needs an app-specific password, Microsoft 365 uses a modern sign-in.
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Office 365 and Microsoft 365
A quick word to clear up the names, since people search for both. Office 365 was renamed Microsoft 365, they are the same service, so migrating Yahoo to Office 365 and to Microsoft 365 mean exactly the same job. And to answer a common question, Yahoo is not a Microsoft service, so moving to Microsoft 365 means copying your Yahoo mail into a separate Microsoft mailbox, it is a genuine migration between two providers.
Both Yahoo and Microsoft 365 speak IMAP, which is what makes the move possible. How you do it depends mostly on how many mailboxes you are moving.
Which route fits your scale?
There are three honest routes, and the right one comes down to whether you are an admin moving a whole organization or a single user moving one account.
One account or a whole organization, the scale decides the route.
Same product, two names, and each side signs in its own way.
“A lot of old guides still tell you to switch on less secure apps in Yahoo, but that option is gone, you use an app-specific password now, and nothing connects until you do. The other thing worth knowing is that if you are an admin moving a team, you do not need a third-party tool at all, Microsoft 365 has an IMAP migration built into the admin center. Point it at Yahoo with the app passwords and it does the whole batch.” Shubham Dixit, Email Migration reviewer (draft, pending approval)
First, the Yahoo app password
Every route needs this, so do it first. Yahoo blocks your normal password from outside apps and services, and the old less secure apps toggle no longer exists. Instead you generate an app-specific password.
Sign in to Yahoo, open account security, choose Generate app password, and create one for mail. Use that in place of your normal password wherever Yahoo is asked for. The Yahoo IMAP server is imap.mail.yahoo.com, port 993, with SSL. On the Microsoft 365 side you sign in the modern way, through a Microsoft sign-in window.
Many mailboxes, the admin migration
If you are moving a whole organization, Microsoft 365 has this built in, so you do not need extra software. It is the standard way to migrate mailboxes into Microsoft 365 from an IMAP service like Yahoo.
Create the users in 365 first. Each Yahoo user needs a Microsoft 365 mailbox and licence already in place, that is the destination.
Open the IMAP migration. In the Exchange admin center, go to Migration, add a migration batch, and choose Migrate to Exchange Online then IMAP migration.
Give it the Yahoo details. Upload a CSV listing each Yahoo address and its app-specific password, set the IMAP server to imap.mail.yahoo.com on port 993 with SSL, and start the batch. Microsoft 365 then pulls each mailbox in and reports when it is done.
One mailbox, Outlook and drag
For a single account, the free route is to let Outlook hold both mailboxes and move the mail between them.
Add both accounts. In Outlook, add your Yahoo account as IMAP using imap.mail.yahoo.com and the app-specific password, and add your Microsoft 365 account with its normal Microsoft sign-in.
Drag Yahoo into 365. Open your Yahoo folders, select the mail, and drag it into a folder under the Microsoft 365 account. Because it is IMAP, it uploads to 365 and appears in your mailbox, with attachments and folders intact.
The simplest way, a tool
If you do not have admin access, or you just want it done without setting up Outlook, a migration tool moves Yahoo straight into Microsoft 365 over IMAP. The PCDOTS Email Converter connects to your Yahoo account, reads the mailboxes, and sends them into Microsoft 365 in bulk, keeping folders, attachments and dates, and it can filter by date, folder or field so you move only what you want. It runs on Windows and uses the Yahoo app-specific password with your 365 sign-in. A free version moves the first ten items per folder so you can test it first.
The tool route, for one mailbox or without admin access.
Here are the steps with the screens.
Step 1. Install and run the software on Windows, then open the menu.
Step 2. Choose Email Account, Add Account, and enter your Yahoo address with the app-specific password.
Step 3. Open Export and choose Office 365 as the destination.
Step 4. Sign in to your Microsoft 365 account and Save to start the migration.
For related Yahoo jobs see our guides to save Yahoo emails to a computer and backup Yahoo Mail emails, and for another move into 365, migrate Zimbra to Office 365.
The methods compared
Match the route to how many mailboxes you are moving and your access.
| Method | Best for | Good to know |
|---|---|---|
| 365 admin IMAP migration | A whole organization, free | Needs admin, CSV of app passwords |
| Outlook, drag Yahoo into 365 | One mailbox, free | Both accounts added, drag by hand |
| Email Converter tool | One mailbox, no admin | Windows, migrates over IMAP |
Frequently asked questions
Is Office 365 the same as Microsoft 365?
Yes. Office 365 was renamed Microsoft 365, so migrating Yahoo to either means the same thing, moving your Yahoo mail into a Microsoft 365 mailbox.
Why can I not enable less secure apps in Yahoo?
Yahoo removed that option. You now generate an app-specific password in your Yahoo account security and use it in place of your normal password.
How do I migrate many Yahoo mailboxes at once?
Use the IMAP migration in the Microsoft 365 Exchange admin center. Upload a CSV of Yahoo addresses with app passwords, set the server to imap.mail.yahoo.com, and start the batch.
Can I migrate one Yahoo account without admin access?
Yes. Add both accounts to Outlook and drag the Yahoo folders into the 365 mailbox, or use a tool that moves Yahoo into Microsoft 365 over IMAP.
Should I use IMAP or POP?
IMAP. It keeps your folders and leaves Yahoo untouched. POP downloads messages and can strip the server, so it is the wrong choice for a migration.
Do folders and attachments survive the move?
Yes. All three routes move over IMAP, which keeps the folder structure and the attachments with each message.
Which route matches your setup
It really comes down to who you are. An admin moving a team should reach for the migration that Microsoft 365 already includes, a CSV of Yahoo addresses with app passwords and the admin center does the batch. A single user moving one account can add both mailboxes to Outlook and drag the mail across, or let a tool carry it over IMAP without any setup. Whichever you pick, generate the Yahoo app-specific password first, because nothing connects without it. So the only question left is the useful one, are you migrating one mailbox or a whole organization?
