Outlook for Mac stopped synching with gmail

Google has changed its login to require oauth 2.0. The usual fix is to delete and re-add the account to email. If you are using pop3 instead imap, be sure to save the on device emails first before deleting the account.

Outlook for Mac can stop syncing for several different reasons. Work through these targeted checks and fixes for a Gmail account that suddenly stopped syncing on all Macs.

1. Confirm Outlook is online and connected

• In Outlook for Mac, open the Outlook menu and make sure Work Offline is not checked.
• On the Tools ribbon, choose Accounts and select the Gmail account.
  • Check the status/indicator for the account. If it shows a problem (for Exchange it would be orange; for Gmail it may show an error), note any error text.
• Use a web browser to sign in to Gmail and verify that mail is working there.

2. Check for known Outlook for Mac sync issues and updates

• There is a known issue where Outlook for Mac can stop syncing when Conditional Access is enabled; this was fixed in version 16.92 (Build 24120731). Even though this is documented for Exchange, installing the latest Outlook for Mac update is important for all account types.
• Update Outlook for Mac to at least 16.92 (Build 24120731) or newer via Microsoft AutoUpdate, then restart Outlook and test sync again.

3. Verify general send/receive conditions Even though Gmail is IMAP and not Exchange, the same basic connectivity checks apply:

• Ensure the Mac has a working Internet connection by opening several websites.
• If using a POP/IMAP profile for Gmail, verify account settings under Tools > Accounts:
  • Correct email address and password.
  • Correct incoming (IMAP/POP) and outgoing (SMTP) server names and ports.
  • If using POP, confirm the port is correct (for example, a similar issue was resolved by changing a POP port from 993 to 995 in another scenario).
• If messages send but do not arrive in Outlook, confirm there are no rules in Outlook moving Gmail messages to unexpected folders (including RSS or custom folders).

4. Clear local cache for the Gmail folders (if using Exchange-like or cached mode) For Exchange accounts, corrupted cache can stop new items from appearing; the same principle can help when Outlook’s local store is damaged:

• In the folder list, Ctrl+click or right‑click a problematic folder (such as Inbox) and select Properties.
• On the General tab, choose Empty Cache.
• Outlook will re-download items from the server. Do this only when the items are safely stored on the server (verify in Gmail web first), because anything not on the server will be removed.

5. Check for firewall, proxy, or network changes If all three Macs stopped syncing on the same date, a shared network or security change is likely:

• If using a corporate or managed network, ask the network administrator whether any firewall or proxy changes were made around April 10 that might block IMAP/SMTP or Outlook connections.
• If a proxy is required on the network, ensure macOS proxy settings are correctly configured in System Settings so Outlook can reach Gmail. If a mail proxy is required, obtain the correct settings from the network admin and configure them in macOS.

6. Remove and re-add the Gmail account (after confirming web access) If the above steps do not restore sync and Gmail works in the browser:

• In Outlook for Mac, go to Tools > Accounts.
• Select the Gmail account and remove it.
• Quit and reopen Outlook.
• Add the Gmail account again and complete the sign-in and consent steps.

7. If nothing works

• Test Outlook for Mac on a different network (for example, mobile hotspot) to rule out local firewall issues.
• If the problem persists even on a different network and after re-adding the account and updating Outlook, gather any error messages shown in Tools > Accounts and in send/receive status, then contact support with those details.

References:

• I can't send or receive messages with Outlook for Mac
• I'm not receiving email or other items in my Exchange account in Outlook for Mac
• Outlook for Mac stops syncing when Conditional Access is enabled
• Why am I not able to receive emails which I used to on my outlook mac. I can send emails without any issues. - Microsoft Q&A
• sync between Gmail Web and microsoft outlook - Microsoft Q&A
• Gmail IMAP won't connect to Classic Outlook - Microsoft Q&A
• Stopped receiving emails on my account. - Microsoft Q&A