You cannot delete a sent Gmail message from the recipient’s inbox for everyone after it has been delivered
You can only use Undo Send within the short cancellation period after sending
To use Undo Send, click Undo in the bottom-left corner immediately after sending
To increase the Undo Send time, go to Gmail Settings
Open See all settings
In the General tab, find Undo Send
Set the cancellation period to 5, 10, 20, or 30 seconds
Save Changes
If the message was already sent and the Undo period passed, you cannot remove it from the recipient’s mailbox
You can delete the email from your Sent folder only
You can ask the recipient to delete the message
If the email was sent from a work or school Google Workspace account, an administrator may have additional controls in some cases