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Summary
Sent an email by mistake? Outlook lets you attempt to recall or replace a message before the recipient reads it. This article explains how to use Recall in Classic Outlook and Undo Send in New Outlook and the web.
Before You Start
- A Microsoft 365 mailbox on Exchange Online.
- Both you and the recipient must be in the same organization (recall only).
Instructions
1. Recall a Message in Classic Outlook
Recall attempts to delete the sent message from the recipient's inbox before they open it.
- Open your Sent Items folder.
- Double-click the email you want to recall to open it in its own window.
- Click the File tab, then select Resend or Recall > Recall This Message.
- If you do not see this option, click Actions > Recall This Message on the Message tab.
- Choose one of the following:
- Delete unread copies of this message — removes it from inboxes.
- Delete unread copies and replace with a new message — lets you send a corrected version.
- Check Tell me if recall succeeds or fails for each recipient if you want a status report.
- Click OK.
Note: If the message itself was fine and the problem is that nobody replied or someone was left off the recipient list, use Resend This Message on that same Resend or Recall menu instead — it sends a clean copy with no
FW:prefix. See How to Resend a Message in Outlook.
2. Use Undo Send in New Outlook and Outlook on the Web
New Outlook and the web app offer a brief window to cancel a message right after clicking Send.
- After clicking Send, look for the Undo button or toast notification at the bottom of the screen.
- Click Undo within the countdown window (default is 10 seconds).
- The message returns to your draft for editing or deletion.
Note: Undo Send is not Recall. The message is held briefly before it goes anywhere, so cancelling costs nothing and works every time — where Recall in Step 1 is a request to pull back a message that has already landed, and fails the moment the recipient has opened it or sits outside your organization.
3. Increase the Undo Send Delay (New Outlook / Web)
Give yourself more time to catch mistakes.
- Click the Settings gear icon.
- Go to Mail > Compose and reply.
- Scroll to Undo send and move the slider to your preferred delay (up to 10 seconds).
- Click Save.
Note: Ten seconds is the ceiling here, and it is short for the messages that matter. When a message is worth a second look — a reply written angry, a figure you want to re-check in the morning — schedule it instead and give yourself hours: How to Schedule an Email to Send Later in Outlook. Schedule send in New Outlook and the web lets you name any future time, message by message. If you are in classic Outlook, Step 3 of that article goes further — a rule that holds every message you send for up to 120 minutes, with nothing to remember. That rule is classic Outlook only.
Troubleshooting
DANGER
Recall only works when both sender and recipient use Exchange within the same organization. If the recipient uses Gmail, Yahoo, or a different tenant, the recall will fail silently.
| Symptom / Error | Potential Cause | Solution |
|---|---|---|
| Recall failed notification | Recipient already read the email | The message cannot be recalled once opened. Send a follow-up apology or correction instead — see "When Recall Can't Save You" below. |
| "Recall This Message" option missing | Using New Outlook or a POP/IMAP account | Recall is a Classic Outlook + Exchange feature. Use Undo Send in New Outlook instead. |
| Undo button did not appear | Undo send delay set to 0 | Increase the delay in Settings > Mail > Compose and reply > Undo send. |
When Recall Can't Save You
Recall has a narrow window: it works only while the message sits unread in a mailbox inside your own organization. If the email went to an outside address — Gmail, a client, a supplier — or the recipient has already opened it, the message is staying where it is. At that point the goal changes from pulling the email back to managing what it said.
Assess what the email contained. Reread it as the recipient will. A typo or a forgotten attachment needs a quick correction and nothing more. A wrong figure, a private remark, or data about someone else needs the rest of this list.
Send the correction or apology now. A prompt, plain follow-up beats hoping nobody noticed. Name the mistake without repeating the sensitive content — a correction can be forwarded too, so it must not contain what you are trying to contain:
My previous email was sent in error — the attachment was not meant for you. Please delete it without forwarding it. Apologies for the confusion.
Adjust the first line to fit ("the figures in it were incorrect", "the draft was the wrong version"), and keep the details themselves out.
If sensitive data reached an outsider, tell your manager and IT immediately. IT has containment options you do not, and every one of them works better early. Ask IT to help contain a misdirected email: state what was sent (for example, "a spreadsheet containing client bank details"), who received it, and exactly when it went out. Speed matters more than embarrassment — to a security team, a fast self-report is the good outcome, not the offence. If the attachment carried a sensitivity label with encryption, say so in the ticket: IT can revoke access to a protected file even after it has left the company. That is a large part of why labels exist — see How to Use Sensitivity Labels in Microsoft 365. And if a policy warning appeared when you clicked Send, that was data loss prevention trying to stop this exact scenario — Understanding DLP: Why Can't I Send This Email? explains what it checks.
Clear the stale address that caused it. Most misdirected email starts with autocomplete offering an old or lookalike address. In a new message, start typing the wrong recipient's name in the To field; when the suggestion list appears, hover over the stale entry and click the X beside it. Removing a suggestion deletes no contact and no email — it only stops Outlook offering that address first next time.