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. Outlook moves all future emails from that sender to your Junk folder automatically.

You can also block a sender without opening their email. Right-click the message in your inbox, then select Block. The sender is added to your blocked list when ready.

To see your full blocked list, go to Settings (the gear icon), then View all Outlook settings. Select Mail, then Junk email. Your blocked senders appear under Blocked senders and domains. You can add addresses manually here or remove someone from the list if you change your mind.

Block a sender in Outlook desktop app

Right-click the email from the sender you want to block. Select Junk, then Block Sender. The sender goes into your blocked list, and their future emails land in Junk.

To manage your blocked senders list in the desktop app, go to File, then Options. Select Trust Center, then Trust Center Settings. Click Blocked Senders. You can add new addresses, remove old ones, or see everyone currently blocked.

Key Takeaways

  • Blocking a sender in Outlook sends their future emails to your Junk folder automatically — they do not disappear, but you will not see them in your inbox.
  • You can block someone by opening their email and clicking the three dots, or by right-clicking the message without opening it.
  • Your blocked senders list is stored in your Junk email settings and can be edited at any time if you need to unblock someone.
  • Blocking works at the email address level, so if a sender uses multiple addresses, you may need to block each one separately.
  • Blocked emails still arrive on Outlook's servers — blocking only hides them from your view and does not prevent the sender from knowing whether you read their mail.

Block emails by subject line or content

Outlook's block feature works on sender addresses only. If you want to filter emails by subject line or keywords, you need to create a rule instead. Go to Settings, then Mail, then Rules. Click Add new rule.

Name your rule something you will recognize, like "Block emails about [topic]". Under When the message arrives, select Subject contains or Body contains, then type the word or phrase you want to catch. Under Do the following, select Move to and choose Junk or Delete. Click Save.

Rules explore to new emails only, not messages already in your inbox. If you want to move existing emails that match your rule, select them manually, then move them to Junk.

Unblock a sender

If you blocked someone by mistake or want to receive their emails again, go to Settings, then Mail, then Junk email. Find the sender under Blocked senders and domains. Click the trash icon next to their address to remove them from the blocked list.

Once you unblock them, their emails will no longer go to Junk automatically. Emails they sent while blocked will still be in your Junk folder — unblocking does not move them back to your inbox.

Difference between blocking and marking as spam

Blocking a sender and marking an email as spam are not the same thing. When you block a sender, only that specific email address goes to Junk. When you mark an email as spam, you tell Outlook's filter that this type of message is unwanted, which helps train the filter for future emails from that sender and similar ones.

Marking as spam is useful when you receive unsolicited bulk mail or phishing attempts. Right-click the email and select Junk, then Report phishing if you believe the email is a scam. This reports the sender to Microsoft as well as moving the email to Junk.

What blocking does not do

Blocking a sender in Outlook hides their emails from you, but it does not prevent them from sending mail to your account. The emails still arrive on Microsoft's servers and land in your Junk folder. If you do not check Junk regularly, you might miss important messages that were blocked by mistake.

Blocking also does not prevent a sender from creating a new email address and contacting you again. If someone is harassing you, blocking individual addresses is a temporary measure. Consider reporting the behavior to your email provider or, if it involves threats, to law enforcement.

Frequently Asked Questions

Can I block an entire domain instead of just one email address?

Yes. In Settings > Mail > Junk email > Blocked senders and domains, you can type a domain name like @example.com instead of a full email address. All emails from anyone at that domain will go to Junk.

Will the sender know I blocked them?

No. Outlook does not notify senders when you block them. Their emails still go through to your account — they just land in Junk instead of your inbox. The sender has no way to know whether you read their mail or where it ended up.

What happens to emails I already received from a blocked sender?

Blocking only affects new emails. Messages already in your inbox stay there. If you want to move old emails from a blocked sender to Junk, select them manually and move them yourself.

Can I block emails from a group or mailing list?

You can block the group's email address, but if the group sends from multiple addresses, you may need to block each one. For mailing lists you no longer want, look for an unsubscribe link at the bottom of the email — that is usually faster than blocking.

If I unblock someone, will their old emails come back to my inbox?

No. Unblocking only stops future emails from going to Junk. Emails that were already moved to Junk stay there. You can move them back manually if you need them.