Block a sender in Outlook on the web

Open the email from the sender you want to block. Look for the three dots (more actions menu) in the top right corner of the email and select it. A dropdown menu appears — choose Block. Outlook moves all future emails from that address to your Junk folder automatically.

If you want to block someone without opening their email, right-click on their name in your inbox list and select Block from the menu. The result is the same: their messages go straight to Junk.

You can see your full blocked list by going to Settings (the gear icon), then View all Outlook settings, then Mail > Junk email. Under "Blocked senders", you'll see every address you've blocked. You can remove someone from this list by clicking the X next to their name if you change your mind later.

Block a sender in Outlook desktop app (Windows or Mac)

Right-click directly on the email in your inbox. A context menu appears — select Junk, then Block Sender. That address is now blocked, and Outlook routes their future emails to your Junk folder.

Alternatively, click the email once to select it, then go to the Home tab at the top. In the ribbon, find the Junk button and click the dropdown arrow next to it. Select Block Sender.

To see your blocked senders list in the desktop app, go to File > Options > Trust Center > Trust Center Settings > Junk Email. Click the Blocked Senders tab. You can add addresses manually here or remove them by selecting the address and clicking Remove.

Key Takeaways

  • Blocked senders' emails go to your Junk folder, not deleted, so you can review them later if needed.
  • In Outlook on the web, use the three-dot menu or right-click on a sender's name to block them.
  • In the desktop app, right-click the email and choose Junk > Block Sender, or use the Home tab ribbon.
  • You can view and unblock addresses anytime through your Junk email settings.
  • Blocking works on individual email addresses, not domain names — if someone uses a different address, you'll need to block that one separately.

What happens when you block someone

When you block an address, Outlook doesn't delete past emails from that sender — they stay in your inbox unless you move or delete them manually. Only new messages from that address go to Junk. This means you can still search for and read old emails if you need to, but you won't see new ones arrive in your inbox.

The blocked sender doesn't receive a notification that you've blocked them. From their perspective, their emails are being sent normally. They won't know the messages aren't reaching your inbox unless you tell them.

Unblock an email address

If you block someone by mistake or want to receive their emails again, you can unblock them. In Outlook on the web, go to Settings > View all Outlook settings > Mail > Junk email. Find the address under "Blocked senders" and click the X next to it.

In the desktop app, go to File > Options > Trust Center > Trust Center Settings > Junk Email > Blocked Senders tab. Select the address you want to unblock and click Remove. After you unblock someone, their emails will arrive in your inbox normally again.

Block a domain instead of a single address

Outlook's built-in block feature works only on individual email addresses. If you want to block an entire domain (for example, all addresses ending in @unwanteddomain.com), you need to use Junk email rules instead.

In Outlook on the web, go to Settings > View all Outlook settings > Mail > Rules. Click Add new rule. Name the rule, then under "When the message arrives", select From and type the domain name (like @unwanteddomain.com). Under "Do the following", choose Move to Junk Email. Click Save.

In the desktop app, go to Home > Rules > Manage Rules & Alerts. Click New Rule, then explore rule on messages I receive. Check the box for From and type the domain. Under "Do the following", select Move it to the Junk Email folder. Click OK and then OK again to save.

When blocking doesn't work

If emails from a blocked sender still appear in your inbox, the sender may be using a different email address each time. Outlook can only block the exact address you specified. Check the "From" line of the new email — if it's a different address, you'll need to block that one too.

Another reason emails might slip through is if they're being sent from a mailing list or group address. In that case, blocking the individual sender won't stop emails from the list. You may need to unsubscribe from the list instead, or create a rule that catches emails with certain keywords in the subject line.

If you're receiving a large volume of unwanted emails from many different addresses, consider using Outlook's Safe Senders list in reverse — only allow emails from people you know, and send everything else to Junk. This is more aggressive than blocking and works better for severe spam problems.

Frequently Asked Questions

Can I block someone without opening their email?

Yes. In Outlook on the web, right-click the sender's name in your inbox list and select Block. In the desktop app, right-click the email itself and choose Junk > Block Sender. You don't need to open the message first.

Will the person I block know that I blocked them?

No. Blocking only affects where their emails land in your account — it doesn't send them any notification. Their emails appear to send normally from their perspective.

Can I block an entire company or domain?

Outlook's block feature works only on individual addresses. To block a whole domain, you need to create a Junk email rule instead. Go to Settings > Rules (on the web) or Home > Rules > Manage Rules & Alerts (desktop), and set up a rule that moves emails from that domain to Junk.

What if I accidentally block someone I want to hear from?

Go to your Junk email settings and find the Blocked Senders list. Click the X next to their address (web) or select it and click Remove (desktop). Their future emails will arrive in your inbox normally again.

Do blocked emails get deleted?

No. Blocked emails go to your Junk folder, not the trash. You can still find and read them if you search your Junk folder. Only emails you manually delete are permanently removed.