Block a sender in Outlook on the web or desktop

To block an email address in Outlook, open the message from the sender you want to block. Click the three dots (more actions menu) at the top right of the email, then select Block. Outlook will move all future emails from that address to your Junk folder automatically.

On the desktop version of Outlook, the process is nearly identical. Open the message, find the sender's name at the top, right-click it, and select Block Sender. You can also access this through the Home tab by selecting the message first, then clicking Junk and choosing Block Sender.

Once you block someone, you won't see their emails in your inbox anymore — they go straight to Junk. You can still see them if you check your Junk folder, and you can unblock the sender at any time if you change your mind.

Key Takeaways

  • Blocking a sender in Outlook moves all their future emails to your Junk folder instead of your inbox.
  • On Outlook web, open the email, click the three-dot menu, and select Block; on desktop, right-click the sender name and choose Block Sender.
  • Blocked senders can still send you emails — they just won't appear in your inbox unless you check Junk.
  • You can unblock a sender later by going to Settings and finding them in your blocked senders list.

Where blocked senders go and what you can still see

When you block someone in Outlook, their emails don't disappear — they move to your Junk folder. This means you retain a record of the messages in case you need them later, but they won't clutter your inbox or trigger notifications.

If you accidentally block someone or change your mind, you can unblock them. In Outlook on the web, go to Settings (the gear icon), then View all Outlook settings, then Mail > Junk email. You'll see a list of blocked senders under "Blocked senders and domains." Click the X next to any name to unblock them.

On desktop Outlook, go to File > Options > Trust Center > Trust Center Settings > Safe Senders. Switch to the Blocked Senders tab to see your full list and remove anyone you want to unblock.

Blocking entire domains instead of single addresses

If you're getting spam from multiple addresses at the same company or domain, you can block the entire domain instead of blocking each address one by one. This stops all emails from anyone using that domain from reaching your inbox.

In Outlook on the web, go to Settings > View all Outlook settings > Mail > Junk email. Under "Blocked senders and domains," type the domain name (for example, spamcompany.com) and click Add. On desktop, use the same Blocked Senders tab in Trust Center Settings and add the domain there.

Blocking a domain is permanent until you remove it, so only use this if you're certain you'll never need emails from that organization. If your company uses that domain, blocking it will also block legitimate work emails.

The difference between blocking and other Outlook filters

Blocking sends emails to Junk automatically, but Outlook also offers other ways to manage unwanted mail. Rules let you automatically move, delete, or flag emails based on sender, subject line, or keywords. Focused Inbox separates important emails from less important ones without deleting anything. Sweep deletes all emails from a sender or with certain words in one action.

Use blocking when you never want to see someone's emails again. Use rules when you want more control — for example, moving emails from a sender to a specific folder instead of Junk. Use Focused Inbox if you want to reduce clutter without losing emails. Each tool handles a different problem, so choose based on what you're trying to accomplish.

What happens when a blocked sender tries to contact you

When you block someone, they don't receive a notification that you've blocked them. They can still send you emails, but those emails land in your Junk folder instead of your inbox. From their perspective, they have no way of knowing whether you received their message, blocked them, or straightforward didn't respond.

If a blocked sender is trying to reach you for something important, they might try a different email address or contact method. If you realize you need to hear from them, you can unblock them and check your Junk folder for their previous messages. Outlook keeps emails in Junk for 30 days by default before deleting them, so there's usually time to recover them if needed.

Blocking emails on Outlook mobile apps

On the Outlook mobile app for iPhone or Android, blocking works similarly to the web version. Open the email from the sender you want to block, tap the three dots at the top right, and select Block. The app will confirm that the sender has been blocked and their future emails will go to Junk.

To see your blocked senders list on mobile, go to Settings (the gear icon at the bottom), then Mail settings, then Blocked senders. You can add senders manually here or remove anyone from your blocked list. The blocked senders list syncs across all your devices, so blocking someone on your phone also blocks them on your desktop and web version.

Frequently Asked Questions

Can I block someone without opening their email?

On Outlook web, you can right-click an email in your inbox list and select Block from the menu without opening it. On desktop, select the email and use the Junk menu. This saves a step if you recognize the sender from the subject line or preview.

Will a blocked sender know I blocked them?

No. Blocked senders receive no notification. Their emails straightforward go to your Junk folder instead of your inbox. They have no way of knowing whether you blocked them, didn't see their message, or chose not to respond.

What if I block someone by mistake?

You can unblock them anytime through Settings. Go to Junk email settings, find the blocked senders list, and click the X next to their name. Any emails they sent while blocked will still be in your Junk folder, and future emails will return to your inbox.

Does blocking someone delete their old emails?

No. Blocking only affects new emails going forward. Old emails from that sender stay in your inbox unless you delete them manually. If you want to remove their past messages, you'll need to find and delete them yourself.

Can I block emails by subject line or keyword instead of sender?

Blocking works by sender address or domain only. To filter by subject line or keywords, use Outlook Rules instead. Rules give you more options, like automatically deleting emails with certain words or moving them to a specific folder.