Block a sender in Outlook with one click

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

If you're using Outlook on the web, the process is identical. If you're using the Outlook desktop app on Windows or Mac, the menu location is the same — three dots in the top right corner of the open message.

Once you block someone, you won't see notifications when they send you mail. Their messages will arrive in Junk, and you can delete them without reading. You can unblock a sender at any time by going to Settings > Mail > Junk email and removing their address from the Blocked Senders list.

Key Takeaways

  • Blocking a sender takes three clicks: open the message, click the three-dot menu, and select Block.
  • Blocked senders' emails go to your Junk folder, not deleted, so you can review them later if needed.
  • Blocking works on Outlook.com, Outlook desktop, and Outlook mobile apps the same way.
  • You can unblock someone later through Settings > Mail > Junk email > Blocked Senders if you change your mind.
  • Blocking a sender is different from marking a single email as spam — blocking stops all future mail from that person.

Why block instead of just deleting

When you delete an email, the sender can still reach you tomorrow. Blocking stops the flow. Every email from that address goes straight to Junk, and you won't get a notification. This matters if someone is sending you repeated unwanted messages — a blocked sender can't interrupt your inbox anymore.

Blocking is also useful for scam emails that come from addresses that look real but aren't. If you receive a fake invoice, a phishing message pretending to be from your bank, or a message claiming you've won something, blocking that sender prevents similar messages from the same address. Scammers often use new addresses, so blocking one won't stop all scams, but it stops that particular source.

The difference between blocking and marking as spam

When you mark a single email as spam, you're telling Outlook that message is unwanted, but the sender can still email you again. Outlook learns from your spam reports and may filter future messages from that sender, but it's not may provide.

Blocking is permanent and when ready. Every message from a blocked sender goes to Junk, no exceptions. If you're getting repeated unwanted mail from the same person or address, blocking is stronger than marking one email as spam.

Blocking on Outlook mobile apps

On the Outlook mobile app for iPhone or Android, open the email you want to block. Tap the three dots at the top right. Tap Block Sender. The sender will be added to your blocked list, and their future emails go to Junk.

The mobile app works the same way as the desktop and web versions. If you block someone on your phone, that block syncs across all your devices — if you use Outlook on your computer and your phone, blocking on one will block on the other.

What happens to emails already in your inbox

Blocking a sender does not move their old emails out of your inbox. Only new messages from that sender go to Junk. If you want to clean up old emails from someone you've blocked, you'll need to delete or move them yourself.

You can select multiple old emails from the same sender and delete them at once. Click the checkbox next to the first email, then hold Shift and click the last email to select a range. Then click Delete or move them to a folder.

Unblocking a sender if you change your mind

Go to Settings (the gear icon in Outlook.com, or File > Options on desktop). Select Mail from the left menu. Click Junk email. You'll see a list called Blocked Senders. Find the address you want to unblock and click the X next to it.

On mobile, go to Settings > Mail > Junk email > Blocked Senders, find the address, and tap to remove it. Once you unblock someone, their emails will go to your inbox again instead of Junk.

Blocking doesn't stop spoofed addresses

Scammers sometimes send emails that look like they come from a trusted company or person, but the actual sender address is different. This is called spoofing. If you block the fake address, the scammer can send you another email from a different fake address tomorrow.

Blocking works best for people you actually know who are bothering you, or for scam emails where the sender keeps using the same address. For widespread phishing campaigns or spoofed emails, blocking individual addresses is less effective. Instead, look for other signs the email is fake — urgent language, requests for passwords, suspicious links — and delete it without clicking anything.

Frequently Asked Questions

Can a blocked sender tell that I blocked them?

No. A blocked sender won't receive any notification. Their emails will go to your Junk folder silently. They have no way to know whether you blocked them, deleted their messages, or straightforward didn't read them.

What if a blocked sender emails me from a different address?

Blocking only stops emails from that specific address. If the same person sends you mail from a new email address, it will go to your inbox. You can block the new address the same way. If someone is harassing you from multiple addresses, consider reporting them to Outlook support or your IT department.

Does blocking a sender delete our conversation history?

No. Blocking only affects new emails. Old messages from that sender stay in your inbox or other folders. If you want to remove the conversation, you'll need to delete those emails yourself.

Can I block an entire company or domain?

Outlook doesn't have a built-in way to block all emails from a domain (like all addresses ending in @example.com). You can only block individual email addresses. If you're getting mail from many addresses at the same company, you may need to block them one at a time or use Outlook rules to filter them automatically.

Will blocking stop emails from group mailing lists?

If you block someone who sends you emails through a mailing list, emails from that list will still arrive — the list's address is different from the person's individual address. To stop getting emails from a mailing list, look for an unsubscribe link at the bottom of the message, or contact the list owner directly.