Quick answer
Recall only works if you and the recipient are on the same Microsoft 365 / Exchange organisation and they haven't opened the email yet. In classic Outlook, open the sent message and choose Recall This Message. It's unreliable — so the real fix is to turn on the Undo Send delay, which holds every message for a few seconds so you can catch mistakes before they leave.
BEFORE YOU START
Recall is not magic — and it's fussy.
It helps to understand what recall actually is. It sends a follow-up instruction asking the recipient's mailbox to delete the original — and that only works when you're both in the same organisation on Microsoft 365 or Exchange, and the message is still unread. Send to a Gmail, Hotmail or any outside address and recall simply can't reach them. If the person has already read it, it's too late. Because of all that, don't rely on recall — the smarter move is the Undo Send delay, which catches the email before it ever leaves your outbox and works for any recipient.
HOW TO RECALL — AND HOW TO SET UP UNDO SEND
Work through these in order.
- Recall in classic OutlookOpen your Sent Items and double-click the message so it opens in its own window. On the Message tab, choose Actions → Recall This Message, then pick whether to delete unread copies or replace them with a new message.
- Recall in new Outlook / Outlook on the webOpen the sent message from Sent Items and look for the Recall message option on the toolbar or ribbon. Microsoft has been rolling out a cloud-based recall for work accounts that can report back whether each recall succeeded — but it still only applies inside your own organisation.
- Check whether it actually workedRecall is quiet about failure. If the recipient had already opened the email, or they're outside your organisation, the recall does nothing — and in some setups they'll even see the recall attempt. Don't assume it worked; if it mattered, follow up with a quick, honest note.
- Turn on Undo Send in Outlook on the webThe reliable safety net: go to Settings → Mail → Compose and reply, find Undo send, and set the delay (up to about 10 seconds on the web). Save. Now every message shows an Undo button for those few seconds after you click Send.
- Turn on Undo Send in the new Outlook for WindowsIn the new Outlook desktop app, open Settings → Mail → Compose and reply and set the Undo send delay — the desktop app allows a longer window (up to two minutes). Pick a delay that gives you time to spot a mistake without slowing your email down.
- Use the Undo button when you slip upAfter sending, watch for the Undo send prompt at the bottom of the screen and click it to pull the message straight back into a draft. Because it acts before the email leaves, it works for any recipient — internal or external.
The honest truth about recall. Outside your own organisation, or once a message has been read, recall simply won't help — and treating it as a guaranteed undo is how confidential emails end up in the wrong hands. Build the habit instead: switch on Undo Send, and for anything sensitive, add the recipients last, after you've written and checked the message. Prevention beats recall every time.
