How to Undo or Delay Sending Emails in Outlook: The Ultimate Guide
This guide introduces the methods to undo sending or delay sending emails in Microsoft Outlook, across all major versions including New Outlook, Classic Desktop Outlook, Outlook Mobile App, and Outlook Web App (OWA).
Have you ever hit "Send" too soon, only to realize moments later that your email went to the wrong person, had missing attachments, or contained sensitive information? You're not alone. While Microsoft Outlook provides various tools to undo or delay email sending, their success depends heavily on the version of Outlook you're using and a few critical conditions. In this comprehensive guide, we'll walk you through all available options—including built-in features and third-party tools like Kutools—so you can avoid email disasters before they happen.
What Is "Undo Send" in Outlook?
Undo/Delay Methods Across Outlook Versions
Best Practices to Avoid Email Mistakes
FAQ: When Recall Works and When It Doesn’t
What Is "Undo Send" in Outlook?
Outlook offers two approaches to stopping unwanted emails:
Select the "Sent Items" folder on the Navigation Pane, and double-click to open the email you sent by mistake.
- Message Recall: Try to retract a message already sent and delivered (only in some versions).
- Delay Delivery: Hold a message in the Outbox before it’s actually sent, giving you time to cancel or edit.
The second method—delay—is far more reliable across versions.
When Should You Use Undo Send
Typical real-life situations include:
- Sent the email to the wrong recipient.
- Forgot attachments or included incorrect files.
- Detected grammar issues or sensitive content.
- Selected the wrong email template.
- Had second thoughts about tone or timing.
Undo/Delay Methods Across Outlook Versions
This section introduces the methods to undo or delay sending emails in Microsoft Outlook, covering all major platforms:
- New Outlook (Windows)
- Classic Desktop Outlook (Microsoft 365, 2016-2024)
- Outlook Web App (OWA)
New Outlook for Windows
Feature: "Undo Send" delay window (5–10 seconds)
Recall is NOT available
✅ How to Enable or Adjust Undo Send in New Outlook:
Step 1. Open New Outlook and click on the gear icon (⚙️) in the top right to open Settings.
Step 2. In the Settings pane, select Mail > Compose and Reply.
Step 3. Scroll to find the Undo Send section. Adjust the slider to set a delay from 0 to 10 seconds.
Step 4. Click Save.
Now, when you send an email, you’ll see an Undo button at the bottom of the screen for the duration you set.
Click the Undo button to cancel sending and return to the email compose window.
| ✔️ Pros | ✖️ Cons |
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😁 Best For:
- Users who want a quick buffer for last-second edits.
- Personal or small business users using cloud-based Outlook.
Classic Desktop Outlook (Microsoft 365, 2016-2024)
Method 1: Recall This Message
Only works under strict conditions (Exchange, unread, same org).
✅ How to Recall Emails in Desktop Outlook:
Step 1. Open Sent Items, double-click the message.
Step 2. Go to the Message tab > Actions > Recall This Message.
Step 3. Choose to delete or replace unread copies.
1️⃣ "Delete unread copies of this message"
📌 What it does:
This option attempts to completely remove the original email from the recipient’s inbox if it hasn’t been read yet.
✅ Best used when:
- The message was sent by mistake.
- You sent it to the wrong person.
- The content is sensitive or inappropriate.
- If successful, the recipient won’t see the email at all—or may only see a notice that it was recalled..
2️⃣ "Delete unread copies and replace with a new message"
📌 What it does:
This option tries to delete the original unread message and immediately lets you send a replacement email to the same recipients.
✅ Best used when:
- You want to correct the content of an email you just sent.
- The recipient and subject are still valid, but the message itself needs fixing.
- The content is sensitive or inappropriate.
- If successful, the recipient won’t see the email at all—or may only see a notice that it was recalled..
Step 4. Track results in Tracking tab.
⚠️ Important notes:
It only works under the same conditions as above: Exchange + unread + same organization.
If the recall fails, the recipient may end up seeing:
- The original message.
- The recall notification.
- And your new replacement message.
| ✔️ Pros | ✖️ Cons |
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😁 Best For:
- Internal corporate environments using Microsoft Exchange.
- Users who send within one company or network.
Recommended: Kutools for Outlook's Recall Emails
Kutools for Outlook's Recall Email enhances the traditional recall feature by allowing users to:
- Recall multiple sent emails at once (batch operation).
- View a centralized dialog box showing the status of all recall attempts.
- Retry or cancel failed recall requests efficiently.
✅ How to Recall Multiple Emails in Desktop Outlook:
Step 1. Select the emails that you want to recall, and go to the Kutools tab in Outlook.
Step 2. Click Recall Multiple Messages.
Step3. Review the status of all recall attempts.
Step 4. Review results in a dedicated Recall Status Manager dialog.
| ✔️ Pros | ✖️ Cons |
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😁 Best For:
- Users who frequently need to correct multiple sent emails.
- Admins or team leads who manage mass communication.
Method 2: Delay Send via Rules
✅ How to Delay Send Every Email in Desktop Outlook:
Step 1. Home > Rule > Manage Rules & Alerts.
Step 2. Select New Rule in the Rules & Alerts dialog.
Step 3. Choose Apply rule on messages I send, and click Next.
Step 4. Leave the Select Conditions empty and directly click Next, then check defer delivery by a number of minutes. And then click a number of.
Step 5. Set delay (1–10 minutes), click OK, click Finish.
| ✔️ Pros | ✖️ Cons |
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😁 Best For:
- Professionals who often catch mistakes after hitting send.
- Anyone dealing with sensitive info or frequent mis-sends.
Recommended: Kutools for Outlook's Global Delay Send + Undo Button
Kutools for Outlook offers an advanced Delay Email feature that lets you automatically delay all outgoing emails by 5 to 60 seconds. During this delay period, you’ll also see an Undo button for each email, giving you a chance to instantly cancel the send and revise the message.
✅ How to Set Delay Email with Kutools in Desktop Outlook:
Step 1. Click Kutools > Delay Email > Modify select the delay time. And set the delay time. Confirm by clicking OK.
Step 2. Click Kutools > Delay Email and click OK to activate the feature.
Now all outgoing emails will be sent with a delay of x seconds.
After you click Send, the email is held in the Outbox.
If you click Undo during the delay time: The message is not sent. You are returned to the email compose window, with your draft intact and editable.
If you click Send Immediately: The message will be sent immediately.
| ✔️ Pros | ✖️ Cons |
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😁 Best For:
- Users who want a second chance to revise emails right after sending.
- Anyone dealing with sensitive info or frequent mis-sends.
- Those who want Gmail-like Undo in Outlook desktop.
Kutools for Outlook also includes a Schedule Email feature, allowing you to send emails at a specific future time—ideal for coordinating with recipients across different time zones.
Outlook Web App (OWA)
Offers "Undo Send" (5–10 sec window), no recall support
✅ How to Undo Send in Web Outlook:
Step 1. Open Outlook Web > Settings (⚙️) > View all Outlook settings.
Step 2. Go to Mail > Compose and Reply.
Step 3. Scroll to Undo send section and set the delay time (5 or 10 seconds) > Save.
Now, when you send an email, you’ll see an Undo button at the bottom of the screen for the duration you set.
Click the Undo button to cancel sending and return to the email compose window.
| ✔️ Pros | ✖️ Cons |
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😁 Best For:
- Users who prefer web-based email access.
- Light email senders needing basic undo.
Best Practices to Avoid Email Mistakes
Since "Recall This Message" often fails, prevention is the better strategy.
Recommended Tactics:
- Enable Delay Send (1–3 mins) in desktop Outlook via rules.
- Set Undo Send to 10 seconds in New Outlook and Web versions.
- Use Kutools for extended delay.
Suggested Setup by Version:
| Version | Suggested Delay | Recommended Tool |
| New Outlook | 0-second Undo Window | Built-in |
| Classic Desktop | 1–3 minute Delay Rule + Kutools' Delay Email Feature | Kutools |
| Web App | Max 10-second Delay | Optional server rule |
FAQ: When Recall Works and When It Doesn’t
Outlook's Recall This Message feature is powerful in theory—but in practice, it only works under very specific conditions. Here’s why your recall might succeed in some cases and fail in others.
✅ When Recall Works (Success Conditions):
- Both sender and recipient are using Microsoft Exchange.
- The email must be within the same Exchange organization or Microsoft 365 tenant.
- The recipient has not yet opened the message. (If the email is already read or previewed, recall will automatically fail..)
- The email is still in the recipient's Inbox. (If the message has been moved by a rule or by the user to another folder, recall won’t work.)
- The recipient is using Outlook desktop (not mobile or web).
- No interfering mail rules or third-party email clients. (Custom rules, forwarding, or external client apps (like Apple Mail) can break the recall process.)
❌ Why Recall Fails (Common Failure Reasons):
- The recipient opened the email before the recall arrived. Once it's opened, recall is no longer possible.
- The email must be within the same Exchange organization or Microsoft 365 tenant.
- The recipient’s email is not hosted on Microsoft Exchange. (Gmail, Yahoo, Outlook.com, and IMAP-based accounts don’t support recall.)
- The email is still in the recipient's Inbox.(If the message has been moved by a rule or by the user to another folder, recall won’t work.)
- The recipient is outside your organization.(Recall typically works only within the same Exchange environment (internal use only).)
- The recipient is using Outlook Web App or Mobile
- The message was moved or affected by rules.
- User permissions or server policies block recall.
Related Articles:
Delete/recall a sent email before recipients reading in Outlook
Recall or retract a sent message in Outlook
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