Block a sender in Outlook on the web

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

If you want to block someone without opening their email, right-click the message in your inbox list and choose Block. The result is the same — their messages go straight to Junk.

To see a list of everyone you have blocked, go to Settings (the gear icon), then View all Outlook settings, then Mail, then Junk email. Your blocked senders appear under Blocked senders and domains. You can remove anyone from this list by clicking the X next to their address.

Block a sender in Outlook desktop app

Right-click the email from the person you want to block. Select Junk, then Block Sender. Outlook adds their address to your blocked list and sends their future messages to Junk.

You can also open an email and go to the Home tab at the top. Click Junk (in the Delete group), then Block Sender.

To manage your blocked list in the desktop app, go to File, then Options, then Trust Center, then Trust Center Settings, then Junk Email. Click the Blocked Senders tab to see everyone you have blocked and remove anyone you no longer want to block.

Key Takeaways

  • Blocking a sender in Outlook moves their future emails to your Junk folder instead of your inbox.
  • In Outlook on the web, click the three dots on a message and select Block, or right-click and choose Block from the list view.
  • In the Outlook desktop app, right-click a message, select Junk, then Block Sender.
  • You can unblock someone at any time by finding their address in your blocked senders list and removing them.
  • Blocking only affects new messages — emails already in your inbox stay there unless you delete them manually.

What happens when you block someone

When you block an email address, Outlook does not delete their old messages or notify them that they are blocked. Their emails straightforward arrive in your Junk folder instead of your inbox. You can still read them if you check Junk, but they will not interrupt your workflow.

If someone sends you an email from a different address, that message will not be blocked — blocking only applies to the specific email address you chose. If a sender switches addresses frequently, you may need to block multiple addresses.

Unblock a sender

In Outlook on the web, go to Settings, then View all Outlook settings, then Mail, then Junk email. Find the address you want to unblock under Blocked senders and domains and click the X next to it.

In the desktop app, go to File, then Options, then Trust Center, then Trust Center Settings, then Junk Email. Click the Blocked Senders tab, select the address you want to unblock, and click Remove.

Block an entire domain instead of one address

If you want to block all emails from a company or domain (for example, all addresses ending in @example.com), you can block the domain itself. In Outlook on the web, go to Settings, then View all Outlook settings, then Mail, then Junk email. Under Blocked senders and domains, type the domain name (like example.com) and click Add.

In the desktop app, go to File, then Options, then Trust Center, then Trust Center Settings, then Junk Email. Click the Blocked Senders tab, click Add, type the domain name, and click OK.

When blocking is not enough

If you receive a large volume of unwanted emails, blocking individual addresses one at a time may not be practical. In that case, you can set up rules to automatically delete or move messages based on words in the subject line, sender address, or message body.

In Outlook on the web, go to Settings, then View all Outlook settings, then Mail, then Rules. Click Add new rule and set conditions (like "from contains" or "subject contains") and actions (like "move to folder" or "delete"). In the desktop app, go to File, then Options, then Mail, then Rules and Alerts, then click New Rule.

Frequently Asked Questions

Does blocking someone in Outlook notify them?

No. Blocking is silent. The sender will not receive any notification that you blocked them. Their emails straightforward go to your Junk folder, and they have no way to know from Outlook itself that you blocked their address.

Can I block emails by subject line instead of sender?

Blocking only works by email address or domain. To filter by subject line, use rules instead. In Outlook on the web, go to Settings, View all Outlook settings, Mail, then Rules. Create a rule with the condition "subject contains" and choose your action (move to Junk, delete, or move to a folder).

What if someone I blocked emails me from a different address?

Blocking applies only to the specific address you blocked. If the sender uses a different email address, those messages will not be blocked and will arrive in your inbox normally. You can block additional addresses as needed, or block their entire domain if they have multiple addresses from the same company.

Can I block emails on my phone?

The Outlook mobile app (for iPhone and Android) does not have a built-in block feature. You can mark messages as spam or junk, but to fully block an address, use Outlook on the web or the desktop app. Once blocked there, the setting applies to all your devices.