However, it’s not possible to do this from the Gmail web interface.

For example, you’re free to do this if youlink your Gmail account to Microsoft Outlook.

you might then search All Mail to find it in the future.

To remove an email you sent from Gmail’s Sent Mail folder while still keeping a copy under All Mail, drag the message from Sent Mail into a different folder.

Why Would You Delete an Email From Sent Mail But Keep an Archived Copy?

This workaround can come in handy for specific situations.

Check with your system administrator before you circumvent auto-purge mechanisms.

The next time you check your mail from the Gmail web interface, the message will be gone from your sent folder, yet you can still find it in the other folder.