Block a sender in Outlook on the web

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

You can also block someone without opening their email. Right-click the message in your inbox, then select Block from the context menu. The result is the same — their emails go straight to Junk.

To see your blocked senders list, go to Settings (the gear icon), then View all Outlook settings. Navigate to Mail > Junk email. You'll see a section called Blocked senders where you can add addresses manually or remove ones you've already blocked.

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

Right-click the email from the person you want to block. Select Junk > Block Sender. Outlook will route their future messages to your Junk folder.

If you want to block someone without opening their email, right-click their name in your inbox list and choose Junk > Block Sender. The effect is identical.

To manage your blocked list in the desktop app, go to File > Options (Windows) or Outlook > Preferences (Mac). Look for Junk Email or Junk settings. You'll find a Blocked Senders tab where you can add or remove addresses.

Key Takeaways

  • Blocking an email address in Outlook sends all future messages from that sender to your Junk folder automatically.
  • In Outlook on the web, click the three dots on an email and select Block; in the desktop app, right-click and choose Junk > Block Sender.
  • You can manage your blocked senders list in Settings (web) or Options/Preferences (desktop) to add addresses manually or unblock someone.
  • Blocking only affects new emails — it does not delete messages already in your inbox from that sender.

What happens after you block someone

Once you block an address, Outlook treats all incoming messages from that sender as junk. The emails still arrive on Outlook's servers, but they bypass your inbox and go directly to the Junk folder. You won't see notifications for their messages, and they won't appear in your main email list.

Blocking does not delete emails that person already sent you. If you want to remove old messages from a blocked sender, you'll need to delete them manually from your inbox or Junk folder. Blocking only affects future mail.

Unblock a sender if you change your mind

Go to your Junk Email settings (in Settings on the web, or Options/Preferences in the desktop app). Find the Blocked Senders list and locate the address you want to unblock. Click the X or Remove button next to their name.

After you unblock someone, their emails will no longer go to Junk automatically. New messages from them will arrive in your inbox like any other sender. Old emails in your Junk folder will stay there unless you move them.

Block a domain instead of a single address

If you're getting spam from multiple addresses at the same company or domain, you can block the entire domain. In your Blocked Senders list, add an entry like @company.com instead of a single email address. Outlook will then block all messages from anyone using that domain.

This is useful for stopping waves of spam from the same source, but be careful — blocking a domain means you won't receive emails from anyone at that organization, including legitimate senders. Only use this method when you're certain you don't need mail from that domain.

Blocked emails still count toward your mailbox storage

Emails in your Junk folder still take up storage space in your Outlook account, even though you don't see them in your inbox. If you're running low on storage, you may want to permanently delete messages from blocked senders rather than just letting them pile up in Junk.

To free up space, go to your Junk folder, select emails from blocked senders, and delete them. In Outlook on the web, you can also set up a rule to automatically delete messages from certain addresses instead of moving them to Junk, though blocking and then deleting periodically is usually simpler.

Frequently Asked Questions

Does the person I block know I blocked them?

No. Blocking in Outlook is silent — the sender receives no notification. Their emails straightforward go to your Junk folder instead of your inbox. They have no way to know whether you blocked them, deleted their messages, or straightforward didn't read them.

Can I block an email address that doesn't exist yet?

Yes. In your Blocked Senders list, you can type in any email address you want to block, even if you've never received a message from it. This is useful if you want to prevent someone from contacting you before they try.

What's the difference between blocking and deleting an email?

Deleting removes one specific message. Blocking prevents all future messages from that sender from reaching your inbox. If you delete an email but don't block the sender, you'll still receive their next message in your inbox.

Will blocked emails go to Junk on my phone if I use Outlook mobile?

Yes. Your blocked senders list syncs across all devices where you use Outlook — web, desktop, and mobile. Emails from blocked addresses will go to Junk on your phone the same way they do on your computer.