- IMAP server
- mail.example.com
- Port
- 993 · SSL/TLS
- Username
- full address
- Password
- mailbox password
cPanel / Dovecot → Microsoft 365
Migrate email from cPanel to Microsoft 365
Moving email from hosting to Microsoft 365 is the standard corporate migration, and it almost always breaks on two things: the shared host’s certificate, and the order of operations around the MX cutover.
- IMAP server
- outlook.office365.com
- Port
- 993 · SSL/TLS
- Username
- full address
- Password
- mailbox password
What breaks on this particular pair
- Shared hosting certificates are issued for the server name, not your domain. Accept the unverified certificate or connect using the name on the certificate.
- If mail.yourdomain already points at the new server, connect to the old one by IP address — the host field accepts it.
- Microsoft 365 requires OAuth 2.0 on the destination; a tenant admin consents once.
- Folder separators differ: Dovecot uses a slash, legacy Courier uses a dot. Without mapping, INBOX.Sent becomes a top-level folder.
- Check the destination mailbox quota first — the transfer stops the moment space runs out.
FAQ
Common questions
What order should I migrate and change MX in?
Move the bulk of the mail while the old server still works, switch MX, then run a second pass a day later to pick up anything that arrived during the transition.
Can I migrate every mailbox on the domain at once?
Yes, via batch mode: upload a CSV of mailboxes and logins, and get one consolidated report at the end.
What about autoresponders and filters?
They do not travel over IMAP — they are server configuration, not messages. Sieve rules and vacation replies must be recreated in Microsoft 365.
Related routes
Other directions
Find out how big your mailbox is. It costs nothing.
Connect two servers, look at the size and decide. Or take the client and keep everything on your side.
Code on GitHub · built on imapsync · no sign-up