Block a sender in Outlook on the web

Open the email from the person you want to block. At the top of the message, select the three dots (more actions menu) on the right side. Choose Block from the dropdown menu. Outlook will move all future emails from that sender to your Junk folder automatically.

Once you block someone, you can still see their messages if you go looking for them in Junk — blocking does not delete old emails. If you change your mind later, you can unblock the sender by going to Settings, then Mail, then Junk email, and removing their address from the Blocked Senders list.

Block a sender in Outlook desktop app (Windows)

Right-click on the email from the sender you want to block. Select Junk from the menu, then choose Block Sender. The sender's address will be added to your blocked list, and their future emails go straight to Junk.

If you do not see the Junk option, make sure you are in your Inbox or another mail folder — the block option does not appear in Calendar or other sections. You can also block someone by opening their email, going to the Home tab at the top, and selecting Junk, then Block Sender.

Block a sender in Outlook for Mac

Open the email from the person you want to block. Click the Home tab at the top of the window. Select Junk, then choose Block Sender. Outlook will send their future messages to your Junk folder.

On Mac, you can also right-click the sender's name in the email header and select Block from the context menu. The result is the same — future emails from that address land in Junk instead of your Inbox.

Block a sender in Outlook mobile app

Open the email from the sender you want to block. Tap the three dots (more actions) at the top right of the message. Select Block Sender. The sender's address goes on your blocked list, and their emails will go to Junk from that point forward.

On both iPhone and Android, blocking works the same way. You can also swipe left on an email (iPhone) or long-press it (Android) to see blocking options, though the three-dot menu is the most reliable method across both platforms.

Key Takeaways

  • Blocking a sender in Outlook sends their future emails to your Junk folder but does not delete messages they already sent you.
  • The block option appears in a three-dot menu on the web version and in the Junk menu on the desktop and mobile apps.
  • You can unblock a sender at any time through your Junk email settings on the web, or by removing them from your blocked list on desktop.
  • Blocking works across all Outlook versions — web, Windows desktop, Mac, iPhone, and Android — though the menu location differs slightly.

What happens after you block someone

When you block a sender, Outlook routes all their future emails to your Junk folder. You will not see notifications for their messages, and they will not appear in your Inbox. The sender does not receive a notification that you blocked them — from their perspective, they straightforward will not know whether you read their email or not.

Emails already in your Inbox before you blocked the sender stay where they are. Blocking only affects new messages. If you want to remove old emails from a blocked sender, you have to delete them manually or use Outlook's sweep feature to delete all messages from that sender at once.

Unblock a sender if you change your mind

On Outlook on the web, go to Settings (the gear icon), then select View all Outlook settings. Choose Mail, then Junk email. Find the sender's address in the Blocked Senders list and click the trash icon next to their name to remove them.

On the desktop app, go to File, then Options, then Trust Center, then Trust Center Settings, then Junk Email. You will see your Blocked Senders list. Select the address you want to unblock and click Remove. On mobile, go to Settings, find Junk email settings, and remove the sender from your blocked list there.

When blocking is not enough

If a sender keeps using different email addresses to contact you, blocking individual addresses becomes tedious. In that case, you can create a rule that sends emails matching certain words or phrases to Junk automatically. On the web, go to Settings, Mail, Rules, and create a new rule. On desktop, go to File, Options, Mail, and then Rules and Alerts.

You can also mark emails as spam or phishing if they appear to be scams. This helps Outlook learn what you consider unwanted and improves filtering for similar messages in the future. If you receive threatening or harassing emails, consider reporting them to your IT department or Outlook support rather than just blocking, since they may need to investigate.

Frequently Asked Questions

Does the sender know I blocked them?

No. The sender will not receive any notification that you blocked them. Their emails will straightforward go to your Junk folder, and they will have no way to know whether you read their message or ignored it.

Can I block an email address that does not exist yet?

No. You can only block addresses that have already sent you an email. If you want to block a sender before they contact you, you would need to create a mail rule instead, which filters based on sender address, subject line, or keywords.

What if I blocked someone by mistake?

You can unblock them through your Junk email settings. On the web, go to Settings, Mail, Junk email, find their address in the Blocked Senders list, and click the trash icon. On desktop, go to File, Options, Trust Center, Trust Center Settings, Junk Email, select their address, and click Remove.

Will blocking stop all emails from that sender?

Blocking stops emails from that specific address. If the sender uses a different email address, those messages will not be blocked. You would need to block each address separately, or create a rule that blocks based on the sender's name or domain instead.

Can I block an entire domain instead of one address?

Not through the block feature directly. You would need to create a mail rule that blocks all addresses from a specific domain. On the web, go to Settings, Mail, Rules, and create a rule that sends emails from that domain to Junk.