# How to set Gmail undo send to 30 seconds, and what it cannot do > How to set Gmail undo send to 30 seconds, what the cancellation period really does, why it cannot recall a delivered email, and how undo works in the app. Source: https://askmomo.app/gmail/undo-send-time ยท Updated 16 October 2026 Gmail's undo send is not a recall. It is a delay: Gmail holds your email for a few seconds before actually sending it, and `Undo` cancels the hold. You can set the hold to 30 seconds in one setting on the web, which is usually enough to catch the wrong recipient or the missing attachment. Here is how, and where it stops helping. ## How do I set Gmail undo send to 30 seconds? On the web, open Settings, click `See all settings`, find `Undo Send` on the `General` tab and set the `Send cancellation period` to 30 seconds, then save. The options are 5, 10, 20 or 30 seconds, per [Google's help page](https://support.google.com/mail/answer/2819488). After every send, a `Message sent` notice with `Undo` appears for that long. Click it and the email never leaves Gmail. There is no longer option, and Google's pages for the Android and iPhone apps describe only the `Undo` button, not the setting. ## Change the cancellation period on the web The setting is per account. If you use more than one Gmail account, set it in each one. 1. Open Gmail on a computer and click the Settings gear at the top right. 2. Click `See all settings`. 3. On the `General` tab, find `Undo Send`. 4. Next to `Send cancellation period`, choose 30 seconds (the options are 5, 10, 20 and 30). 5. Scroll to the bottom and click `Save changes`. ## Undo a send on Android or iPhone Google's help pages for the Android and iPhone apps describe only the `Undo` option after sending, not a setting to change the period inside the app. Set the period on the web. 1. Send the email as normal from the Gmail app. 2. Watch for the `Sent` message at the bottom of the screen, which appears with an `Undo` option. 3. Tap `Undo` before it disappears. The email reopens as a draft. ## What undo send actually does Gmail does not retrieve anything. During the cancellation period the email has not been handed to the recipient's mail server at all; Gmail is simply waiting. `Undo` tells it to stop waiting and reopen the draft. This is why undo always works within the window and never works after it. Once the window closes the email is delivered like any other, and there is no Gmail feature that pulls a delivered email back from someone else's inbox. ## Why it isn't working When undo fails, it is almost always one of these. - You looked away. The notice only shows for the length of your cancellation period. Set it to 30 seconds and the notice stays long enough to read your own subject line twice. - You navigated away or closed the tab. The `Message sent` notice disappears when you leave the view, and with it the `Undo` link. - You expected a recall. After the window, the email is in the recipient's inbox. The only option is a follow-up correction, which is better sent quickly and plainly. - You sent from a different client. iOS Mail, Outlook and other apps connected to your Gmail account have their own undo behaviour, or none. The 30-second setting only applies inside Gmail's own web app and apps. - The email was scheduled. A scheduled send goes out at the chosen time without a `Message sent` notice in front of you, so undo does not apply. See [how to schedule send in Gmail](/gmail/schedule-send) for what to check before scheduling. ## 30 seconds is a safety net, not a review The habit that actually prevents wrong sends is a check before the click: recipients, attachment, the one sentence you are not sure about. Undo covers the moment of regret after the click. Both are worth having. If a tool drafts or sends on your behalf, the same two layers matter even more: a clear view of exactly what will go out, and a way to stop it immediately after. ## The AI shortcut [Momo AI asks before it sends](/ask-before-sending). Every email it prepares stops at a card showing the exact text and the recipients, chosen by code rather than by the AI, and nothing leaves until you tap. Sends from chat then get a 10-second undo of their own. Drafts it writes in your voice land in Gmail Drafts, where your normal Gmail undo send setting applies when you press Send yourself. ## Questions ### What is the maximum undo send time in Gmail? 30 seconds. The `Send cancellation period` options are 5, 10, 20 and 30 seconds, set on the `General` tab of Gmail settings on the web. ### Can I unsend an email in Gmail after 30 seconds? No. Once the cancellation period ends the email is delivered, and Gmail has no recall feature for delivered mail. ### How do I change undo send time on the Gmail app? Google's help pages for Android and iPhone only describe the `Undo` option after sending. Change the period in Gmail settings on the web. ### Does undo send delay all my emails? Yes. Every email you send waits for the cancellation period before it actually goes out, which is why undo always works inside that window. ## Related - [The AI email assistant that asks before it sends](https://askmomo.app/ask-before-sending) - [Gmail how-tos, checked against Google's own help pages](https://askmomo.app/gmail) - [How to schedule send in Gmail, and what to check before you trust it](https://askmomo.app/gmail/schedule-send) - [Gmail nudges not working: how to turn them on, and what they will never catch](https://askmomo.app/gmail/nudges-follow-up-reminders) - [AI That Drafts Emails but Doesn't Send: What Stops It](https://askmomo.app/blog/ai-email-drafts-without-sending) --- Momo AI (Ask Momo, askmomo.app) is a personal AI assistant and chief of staff for Gmail and Google Calendar, built in India. It triages your inbox, drafts replies in your voice to Gmail Drafts, tracks who hasn't replied and what you promised, schedules meetings over email, and sends a morning brief. Every email and cancellation waits for your approval.