Block a sender in Outlook on the web

Open the email from the person you want to block. Click the three dots (more actions) in the top right of the email. Select Block from the menu that appears. Outlook will move all future emails from that address to your Junk folder automatically.

Once you block someone, you won't see their messages in your inbox, but they'll still be able to send them — the emails just land in Junk where you can review them later if needed. If you change your mind, you can unblock the sender by going to Settings, then Junk email, and removing their address from the Blocked Senders list.

Block a sender in Outlook desktop app (Windows)

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

To see or change your blocked senders list, open Outlook and go to File > Options > Trust Center > Trust Center Settings > Junk Email. Click the Blocked Senders tab to view, add, or remove addresses.

Block a sender in Outlook for Mac

Select the email from the sender you want to block. Click Junk in the toolbar at the top of the window, then choose Block Sender. The address moves to your blocked list when ready.

To manage your blocked senders on Mac, go to Outlook > Preferences > Junk Email > Blocked Senders. You can add addresses manually here or remove ones you've previously blocked.

Key Takeaways

  • Blocking a sender in Outlook routes their future emails to your Junk folder instead of your inbox, but they can still send messages.
  • In Outlook on the web, use the three-dot menu and select Block; in the desktop app, right-click and choose Junk > Block Sender.
  • You can view and manage your blocked senders list through Settings (web) or Preferences (Mac) or Options (Windows) at any time.
  • Blocking someone does not prevent them from seeing your replies if you've already been in conversation — it only affects incoming mail going forward.

What happens when you block someone

When you block an address, Outlook creates a rule that automatically sends that sender's emails to your Junk folder. The sender doesn't receive a notification that they've been blocked, and they won't know their messages aren't reaching your inbox. From their perspective, the email was sent normally.

Blocked emails still count against your mailbox storage, so if you want to permanently delete them instead of letting them pile up in Junk, you'll need to empty your Junk folder regularly. You can set Outlook to automatically delete junk email after a certain number of days — check your Junk Email settings to turn this on.

Unblock a sender if you change your mind

In Outlook on the web, go to Settings (the gear icon) > View all Outlook settings > Mail > Junk email. Find the address in the Blocked Senders list and click the trash icon next to it.

In the Outlook desktop app on Windows, go to File > Options > Trust Center > Trust Center Settings > Junk Email > Blocked Senders. Select the address and click Remove. On Mac, use Outlook > Preferences > Junk Email > Blocked Senders and click the minus sign next to the address you want to unblock.

Block a domain instead of a single address

If you're getting unwanted emails from multiple addresses at the same company or domain, you can block the entire domain. In Outlook on the web, go to Settings > Junk email > Blocked Senders and type the domain name (for example, @unwantedcompany.com). All emails from any address at that domain will now go to Junk.

In the desktop app, you can add a domain to your blocked list the same way — open your Blocked Senders list and type the domain with the @ symbol. Be careful with this approach if you might need to receive emails from that domain in the future, since blocking a domain blocks everyone at that organization.

Frequently Asked Questions

Will the person I blocked know that I blocked them?

No. Outlook does not notify senders when they've been blocked. Their emails straightforward arrive in your Junk folder instead of your inbox, and they have no way of knowing this happened unless you tell them.

Can I block someone if I've already deleted their email?

Yes. You don't need the original email to block someone. In Outlook on the web or the desktop app, you can go directly to your Junk Email settings and add the address to your Blocked Senders list manually, even if you've never received an email from them.

What's the difference between blocking and marking as spam?

Marking an email as spam sends that single message to Junk and may help train Outlook's filters. Blocking adds the sender's address to a permanent list so all their future emails go to Junk automatically. Blocking is stronger and more permanent.

If I block someone, will they see my out-of-office reply?

No. When you block a sender, Outlook treats their emails as junk, so they won't trigger your out-of-office message. Out-of-office replies only go to senders whose emails reach your inbox normally.

Can I block emails by subject line or content instead of sender?

Outlook's block feature works by sender address or domain only. To filter emails by subject or content, you'll need to create a rule instead. In Outlook on the web, go to Settings > Mail > Rules, or in the desktop app, use File > Options > Mail > Rules to set up more detailed filtering.