Outlook for Mac (Legacy) keeps restoring deleted Gmail messages

Hi Shawn C,

Gmail's IMAP maps "delete" to removing the Inbox label rather than moving to Trash, so the message still exists on the server. If it's still Unread at the time of deletion, Gmail re-presents it to Outlook, which re-downloads it as a new arrival. Marking it Read first stabilizes the server state before the delete which is why your two-step approach works. Your Outlook.com account behaves differently as it connects via Exchange (EWS), which handles deletions more cleanly.

Few things to try:

1. Adjust Gmail's IMAP settings (Gmail web)

Settings > See all settings > Forwarding and POP/IMAP > IMAP Access:

• Auto-Expunge > Off
• When a message is expunged > Move to Trash

2. Disable IMAP IDLE in Outlook

Outlook > Settings > Accounts > [Gmail] > Advanced:

• Uncheck "Use IMAP IDLE" and set a short sync interval (e.g., 5 min)

3. Mark messages as

Read immediately Outlook > Settings > Reading:

• Set "Mark as read" > 0 seconds

4. (Optional) Re-add Gmail as plain IMAP via App Password

If the above don't fully resolve it, your Gmail may be connected as a Google account type (OAuth) rather than standard IMAP, which can cause unpredictable sync behavior. Re-adding it manually (imap.gmail.com, port 993, SSL) using a Google App Password instead of OAuth registers it as a standard IMAP connection.

Please give these a try and let me know how it goes. Happy to help troubleshoot further if needed.

This behavior is caused by how Gmail labels and read/unread state sync with Outlook for Mac, not something that can be fully corrected by configuration in the legacy client.

Key points from current behavior between Outlook for Mac and Gmail:

1. Gmail labels map to Outlook folders, and Gmail’s system folders (All Mail, Starred, Important) are handled specially in Outlook. Messages can appear to “re‑appear” when Gmail’s server view and Outlook’s local state are not yet aligned.
2. Outlook for Mac relies on the provider’s server for the Read/Unread state. If the server reports a different state than what is shown locally, Outlook updates to match the server. This same pattern is documented for IMAP accounts where Outlook must honor the server’s status and actions.
3. For Google accounts connected using the newer Google account type, there are known mail-sync quirks and limitations (for example, label/folder delays, draft sync asymmetry, shortcut differences). These are server-integration behaviors rather than local settings that can be tuned away.

Because Outlook must follow Gmail’s server state, deleting a message that is still “Unread” on the server can result in the server re‑presenting it to Outlook, which then makes it look like a new arrival. Marking it Read first effectively stabilizes the server state before the delete, which is why the two‑step workaround behaves more reliably.

There is no documented Outlook for Mac (Legacy) setting that changes this Gmail-specific interaction. The supported options are:

• Continue using the mark‑as‑read‑then‑delete workflow.
• Use the “new” Outlook profile for this Gmail account, which uses the newer Google account integration and different handling of Gmail system folders (for example, All Mail mapping to Archive, Starred/Important being removed in favor of Focused/Other and flags).

If the behavior is unacceptable, the only supported way to avoid it in the Microsoft ecosystem is to move the Gmail account to the newer Outlook experience, where Gmail integration is explicitly being aligned with the rest of the Outlook family.

References:

• Known issues syncing Google accounts to the Microsoft Cloud
• Changes coming to your connected Gmail accounts in Outlook
• IMAP Sent Messages (Outlook for Mac) duplicated and unread in Sent Items folder