Follow these steps to restore Gmail send/receive in classic Outlook for Microsoft 365:
- Confirm Outlook build and fixes
- Make sure Outlook is updated to a build that includes the Gmail fixes, especially if seeing errors like:
- “We weren’t able to set up your Google account with IMAP. You may need to make changes to your Gmail settings.”
- “The browser or app may not be secure.”
- Update Outlook: File → Office Account → Update Options → Update Now.
- Re-run Google sign-in consent (classic Outlook)
If Gmail was added previously and now stopped working, the issue can be missing permissions during Google sign-in.
- In Outlook, when the Gmail error appears, look for a Retry link in the error dialog (available starting with Current Channel Version 2412 Build 18324.20168).
- Select Retry to reopen the Google sign-in page.
- During sign-in, on the “Select what Microsoft apps & services can access” screen, ensure the box is checked for:
- “Read, compose, send, and permanently delete all your email from Gmail.”
- Complete sign-in and let Outlook resync.
If the Retry option is not available or does not work, remove the Gmail account from the Outlook profile and add it again, making sure that same permission box is checked during the browser sign-in.
- Verify IMAP is enabled in Gmail
If Outlook reports IMAP/connection errors, confirm IMAP is enabled in Gmail:
- In a browser, go to Gmail.
- Open Settings → See all settings.
- Go to Forwarding and POP/IMAP.
- Under IMAP access, select Enable IMAP.
- Select Save Changes.
- Check Gmail server settings (if using manual setup)
If the account was added manually in Outlook, verify the Gmail server settings match:
- Incoming (IMAP) server:
imap.gmail.com
- Outgoing (SMTP) server:
smtp.gmail.com
- SSL: Yes
- TLS: Yes (if available)
- Authentication: Yes
- Port (SSL): 465
- Port (TLS/STARTTLS): 587
- Username: full Gmail address
- Password: Gmail password (or app password if using that method).
- If Gmail will not add at all in classic Outlook
If adding Gmail fails with security or IMAP setup errors in classic Outlook:
- Ensure Outlook is on a build where the Gmail sign-in fix is available (for example, Current Channel Version 2404 Build 17531.10000 or later for the sign-in window fix).
- After updating, try adding the Gmail account again so Outlook can use the newer browser-based sign-in flow.
If all of the above are correct and Gmail still does not send or receive, remove the Gmail account from Outlook, restart Outlook, and add the account again using the automatic Google account option, carefully granting the full email access permission during sign-in.
References: