Block a sender in Outlook on the web

Open the email from the person 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 messages from that sender to your Junk folder automatically.

Once you block someone, you can still see that they sent you a message — it just arrives in Junk instead of your inbox. If you change your mind, go to Settings > Mail > Junk email, find the sender's address in the Blocked senders list, and click the X to remove them.

Block a sender in Outlook desktop (Windows and Mac)

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

To unblock someone in the desktop version, go to Home > Junk > Junk Email Options. Click the Blocked Senders tab, select the address you want to remove, and click Remove.

Key Takeaways

  • Blocking a sender in Outlook routes their future emails to your Junk folder rather than deleting them outright.
  • The block button appears in the three-dot menu on the web version and under the Junk menu in the desktop app.
  • You can unblock someone at any time through your Junk email settings or Blocked Senders list.
  • Blocking only affects new messages — emails already in your inbox stay where they are unless you delete them manually.
  • If someone uses multiple email addresses, you may need to block each address separately.

What happens when you block someone

When you block a sender, Outlook does not delete their messages — it sends them to Junk. This means you can still find and read them if you need to, but they will not clutter your inbox or trigger notifications.

The block applies only to messages from that exact email address. If the same person emails you from a different account, those messages will arrive in your inbox normally. You would need to block each address separately.

Block an entire domain

If you are receiving unwanted mail from many addresses at the same company or service, you can block the whole domain. In Outlook on the web, go to Settings > Mail > Junk email. Under Blocked senders, type the domain name (for example, @unwanteddomain.com) and click Add.

In the desktop version, open Junk Email Options from the Home tab, click the Blocked Senders tab, and type the domain address. This stops all email from anyone using that domain from reaching your inbox.

Use rules to sort mail automatically

Blocking sends mail to Junk, but rules let you organize email in other ways. In Outlook on the web, click Settings > Mail > Rules. Click Add rule, name it, and set conditions — for example, "if the sender is [address], move to [folder]."

Rules work best when you want to keep emails but file them automatically. You might route newsletters to a folder, send messages from your manager to a priority folder, or move certain keywords to a specific location. Blocking is simpler if you just want the sender out of your inbox.

Recover blocked emails

If you blocked someone by mistake, their recent emails are still in your Junk folder. Unblock them through your Blocked Senders list, then move the messages back to your inbox manually. Open Junk, find the emails, right-click, and select Move > Inbox.

Unblocking does not automatically move old messages — you have to do that yourself. Going forward, new messages from that sender will arrive in your inbox normally.

When blocking is not enough

Blocking works for individual senders, but if you are receiving a high volume of unwanted mail, your Junk filter settings may need adjustment. In Outlook on the web, go to Settings > Mail > Junk email and choose your filter level: Standard, Safe, or Strict. Strict catches more spam but may filter legitimate mail.

If blocking and filter adjustments do not stop the problem, the email may be phishing or a scam. Do not click links or read attachments from suspicious messages. Report the email as phishing in Outlook (click the three dots and select Report phishing), which helps protect other users.

Frequently Asked Questions

Does blocking someone in Outlook delete their old emails?

No. Blocking only affects new messages going forward. Emails already in your inbox stay there. You must delete them manually if you want them gone.

Can I block someone without opening their email?

In Outlook on the web, right-click the message in your inbox and select Junk > Block Sender. In the desktop app, right-click and choose Junk > Block Sender. You do not need to open the email first.

What is the difference between blocking and marking as spam?

Blocking adds the sender to your Blocked Senders list and routes all their future mail to Junk. Marking a single message as spam trains your filter but does not block the sender. That person's next email might still reach your inbox if the filter does not catch it.

Will the sender know I blocked them?

No. Outlook does not notify senders when you block them. They will not receive a bounce-back message or any indication that their emails are going to your Junk folder.

Can I block emails by subject line or keyword?

Blocking targets the sender's address, not subject lines. To filter by keyword, use Rules instead. Create a rule that moves emails containing certain words to a folder or Junk.