Undo send

Undo send holds your message for a few seconds after you hit Send, so you can catch a typo, a wrong recipient, or a forgotten attachment before it goes out. It works in the Shipmail inbox for both new emails and replies.

Last updated July 2, 2026

Choose your window

Set how long the window lasts in Settings > Preferences, under Undo send. The setting is per person, so each teammate picks their own. The default window is 5 seconds.

Window	What it means
Off	Send immediately, no undo.
5 seconds	A quick safety net. The default.
10 seconds	A bit more room to reconsider.
20 seconds	More time to reconsider.
30 seconds	The longest window.

How it works

Hit Send. The composer closes and a toast shows a "Sending in..." countdown with an Undo button, so you are free to move on.
Change your mind? Click Undo in the toast before the countdown ends. The composer reopens with everything intact, including attachments.
Do nothing. When the countdown reaches zero, the email sends.
Close the tab. The message is held on Shipmail servers, not just in your browser, so it still sends if you close the tab or lose connection during the countdown.

Good to know

Undo send applies to the Shipmail inbox. Messages sent through the API are not held.
Scheduling a send for a specific future time is separate. Cancel a scheduled email any time before it goes out from the Scheduled view.
With undo on, an email appears in your Sent folder and the conversation once the window ends, not the instant you click Send.