- IMAP server
- outlook.office365.com
- Port
- 993 · SSL/TLS
- Username
- full address
- Password
- mailbox password
Microsoft 365 → Gmail
Migrate email from Microsoft 365 to Gmail
Migrating Microsoft 365 to Gmail needs OAuth on the source side, because Exchange Online no longer accepts a plain password. On the Google side you need an app password or OAuth as well — plus enough storage quota to land in.
- IMAP server
- imap.gmail.com
- Port
- 993 · SSL/TLS
- Username
- full address
- Password
- app password
What breaks on this particular pair
- Microsoft 365 as a source requires OAuth 2.0. App passwords exist in some tenants but Microsoft is phasing them out.
- Exchange Online throttles bulk reads to roughly 0.5 GB per hour. This is not configurable.
- Google Workspace quota is shared across Mail, Drive and Photos. Confirm the plan can hold 30 GB before you start.
- Conversation History and Notes move as ordinary folders but will look different in Gmail than they did in Outlook.
FAQ
Common questions
Do I need tenant admin access?
For a single mailbox the user’s own permissions are enough. For a batch migration an admin grants consent once for the whole tenant.
Do Outlook categories survive?
No. Categories are an Exchange property, not an IMAP one. Read and answered flags transfer; coloured categories do not.
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