The fastest way to block someone in Outlook

Open the email from the sender you want to block. Right-click on their name or email address at the top of the message, then select Block Sender from the menu. Outlook will move that sender's future emails to your Junk folder automatically.

If you are using Outlook on the web, click the three dots (more actions) at the top right of the email, then choose Block. The result is the same — emails from that address go straight to Junk.

You do not need to do anything else. Once blocked, you will not see notifications from that sender, and their messages will not clutter your inbox.

Key Takeaways

  • Right-click a sender's name in any email and select Block Sender to send all their future messages to Junk automatically.
  • Blocking does not delete emails already in your inbox — only new messages from that sender are affected.
  • You can unblock a sender at any time through Junk Email Options in the Home tab of Outlook desktop, or through Settings on Outlook web.
  • Blocking a sender is different from marking a single email as spam, which only trains Outlook's filter but does not prevent future messages.
  • If someone is using multiple email addresses to contact you, you will need to block each address separately.

Where blocked senders end up

When you block a sender in Outlook, their emails do not disappear — they go to your Junk folder instead. This means you can still find them if you need to, but they will not show up in your inbox or trigger notifications.

Outlook keeps blocked senders on a list. If you ever need to read an email from someone you blocked, you can check your Junk folder. The folder shows you everything Outlook thinks is spam, including messages from blocked senders and emails flagged by Outlook's automatic filters.

How to unblock a sender

If you block someone by mistake, or if you want to hear from them again, you can remove them from the blocked list. In Outlook desktop, go to the Home tab, click Junk, then select Junk Email Options. Click the Blocked Senders tab to see your list.

Find the sender you want to unblock and click Remove. Their emails will now go to your inbox like any other message. In Outlook on the web, go to Settings (the gear icon), then Mail, then Junk email. You will see your blocked senders list there and can remove anyone from it.

Blocking versus marking as spam

Blocking a sender and marking a single email as spam are two different actions. When you mark one email as spam, you are training Outlook's filter to recognize similar messages in the future — but emails from that sender can still reach your inbox.

Blocking a sender is stronger. It puts all their emails in Junk immediately, without waiting for Outlook's filter to learn. If someone is repeatedly sending you unwanted messages, blocking is the faster choice. If you are unsure whether future emails from someone will be unwanted, marking one email as spam gives Outlook a chance to filter them without blocking the sender completely.

Blocking multiple addresses from the same person

Some senders use more than one email address. If someone keeps contacting you from different addresses, you will need to block each one separately. Outlook does not have a way to block all variations of a name or domain at once.

When you notice a new address from the same person, right-click it and select Block Sender just as you would for any other email. Keep doing this each time they contact you from a new address. If the problem continues, consider using Outlook's rules feature instead, which can block entire domains — for example, blocking everyone at a particular company's email system.

Using rules to block senders at a domain level

If you want to block all emails from an entire company or email domain, Outlook's rules feature gives you more control than the Block Sender button. In Outlook desktop, go to Home, click Rules, then Create Rule. You can set up a rule that sends all emails from a specific domain (like @companyname.com) to Junk automatically.

This approach works when one organization is sending you repeated unwanted messages from multiple employee addresses. You can also create rules that move emails to Junk based on keywords in the subject line or message body, which is useful if you are getting similar spam from many different senders.

What happens to emails already in your inbox

Blocking a sender does not touch emails that are already in your inbox. If you have ten messages from someone and then block them, those ten messages stay where they are. Only new emails from that sender will go to Junk.

If you want to clean up old messages from a blocked sender, you can delete them yourself or move them to Junk. Outlook will not do this automatically when you block someone.

Frequently Asked Questions

Can a blocked sender tell that I blocked them?

No. When you block someone, they do not receive any notification. Their emails still go out, but they land in your Junk folder instead of your inbox. From their perspective, they have no way to know whether you blocked them, marked them as spam, or simply did not read their message.

What if I block someone by mistake?

You can unblock them immediately. Go to Junk Email Options (in Outlook desktop) or Junk email settings (on Outlook web), find their address in the Blocked Senders list, and click Remove. Their future emails will go to your inbox again, and you can also move any of their messages from Junk back to your inbox if you want to keep them.

Does blocking a sender stop them from seeing my read receipts?

No. Blocking only affects where their emails land in your inbox. If you have read receipts turned on, a blocked sender will still receive a notification when you open their email. If you do not want them to know you read their message, you will need to turn off read receipts in your Outlook settings.

Can I block emails based on subject line or keywords?

Yes, but you need to use rules instead of the Block Sender button. Create a rule in Outlook that moves emails with specific keywords to Junk. This is useful for blocking newsletters or notifications you no longer want, even if they come from different senders.

What if someone I blocked emails me from a new address?

Outlook will not recognize the new address as coming from a blocked sender, so the email will go to your inbox normally. You will need to block the new address separately. If this keeps happening, consider creating a rule that blocks the entire email domain instead.