Microsoft 365 (Office 365) IMAP and SMTP settings
The server settings to add an address on your own domain, hosted with Microsoft 365 (Office 365), to any mail app.
Exchange Online requires OAuth2 for IMAP, and an organization admin may have IMAP turned off. A mail app without Microsoft sign-in cannot connect.
| Incoming mail (IMAP) | |
|---|---|
| Server | outlook.office365.com |
| Port | 993 |
| Security | SSL/TLS |
| Outgoing mail (SMTP) | |
| Server | smtp.office365.com |
| Port | 587 |
| Security | STARTTLS |
| Sign-in | |
| Username | Your full work or school email address |
| Password | Sign in with Microsoft (OAuth2); basic password sign-in is blocked for IMAP. |
From Microsoft Learn: POP3 and IMAP4 in Exchange Online. Check there if something has changed.
Before you start
- Microsoft has turned off basic authentication for IMAP in Exchange Online, so the mail app must use OAuth2.
- An admin can turn IMAP off for a user, and IMAP is off when the organization uses Entra security defaults.
- Microsoft plans to turn off basic authentication for SMTP sending by default for existing organizations at the end of December 2026.
Use Microsoft 365 (Office 365) in a native Mac app
Bloop.email signs in to Microsoft accounts on Microsoft's own page, so you won't need to type these settings at all. See how to add it.