Block a sender in Outlook on the web and desktop
To block an email address in Outlook, open any message from that sender, click the three dots (more actions) at the top right, and select Block. The sender's future messages go straight to your Junk folder. On desktop Outlook, right-click the sender's name and choose Block Sender from the menu instead.
Once you block someone, you won't see their messages in your inbox, but they still arrive in Junk where you can review them if needed. Outlook keeps a list of blocked senders, so you can unblock someone later if you change your mind. This is the fastest way to stop unwanted mail from a single person or business.
Blocking works the same way whether you use Outlook.com, Outlook on Windows, or Outlook on Mac. The blocked sender cannot tell they've been blocked — they won't receive a notification, and their messages straightforward fail to reach your inbox.
Key Takeaways
- Blocking a sender sends their future messages to Junk instead of your inbox, but does not delete messages already received.
- You can block an email address from any message by clicking the three dots and selecting Block, or by right-clicking the sender's name on desktop.
- Outlook stores your blocked senders list and lets you unblock addresses at any time through Settings.
- Blocking a domain (like @example.com) requires the desktop version of Outlook and stops all mail from anyone at that company.
- Blocked messages still arrive in Junk, so you can check them later if a legitimate sender was mistakenly blocked.
Block an entire domain in Outlook desktop
If you receive unwanted mail from multiple people at the same company, block the entire domain instead of individual addresses. This only works in Outlook desktop (Windows or Mac), not in Outlook on the web. Open any message from that domain, right-click the sender's name, and choose Block Sender. Outlook will ask whether you want to block just that address or the entire domain — select the domain option.
Blocking a domain stops all future messages from anyone with an email address at that company. For example, blocking @example.com will catch mail from sales@example.com, support@example.com, and any other address ending in that domain. This is useful when a company repeatedly sends unwanted messages from different departments or team members.
Domain blocking does not affect messages you've already received — those remain in your inbox unless you delete them manually. If you later need to receive mail from that domain, you can unblock it through your blocked senders list.
Find and manage your blocked senders list
Outlook keeps a record of every address and domain you've blocked. In Outlook on the web, go to Settings (the gear icon), then View all Outlook settings, then Mail > Junk email. You'll see a Blocked senders section listing everyone you've blocked.
In Outlook desktop on Windows, open File > Options > Trust Center > Trust Center Settings > Safe Senders & Blocked Senders > Blocked Senders. On Mac, go to Outlook > Preferences > Junk Email > Blocked Senders. From any of these screens, you can remove addresses from the list if you want to receive their mail again.
Check this list occasionally if you block senders frequently. Sometimes a legitimate contact gets blocked by mistake, and you won't know why their messages stopped arriving until you review the list.
Unblock a sender you blocked by mistake
If you blocked someone and now want to receive their messages again, find them in your blocked senders list and remove them. In Outlook on the web, navigate to Settings > View all Outlook settings > Mail > Junk email, find the address in Blocked senders, and click the trash icon next to it. The sender is now unblocked.
In Outlook desktop, open the blocked senders list (the path depends on your version — see the section above), select the address you want to unblock, and click Remove. Their future messages will go to your inbox normally again, though messages they sent while blocked remain in Junk.
Unblocking takes effect when ready. The next message from that sender arrives in your inbox instead of Junk, so you won't miss important mail if you unblock someone by mistake.
Use Safe Senders to prevent blocking mistakes
Outlook has a Safe Senders list that works opposite to blocking — addresses on this list always reach your inbox, even if they look suspicious. Add important contacts here to make sure you never miss their messages. In Outlook on the web, go to Settings > View all Outlook settings > Mail > Junk email and add addresses to Safe senders and domains.
In Outlook desktop, follow the same path to Trust Center Settings > Safe Senders & Blocked Senders, then click Safe Senders and add the address. You can also add entire domains here — for example, adding @company.com ensures all mail from that company reaches your inbox.
The Safe Senders list is especially useful for business contacts, banks, and services that send automated messages. If you're worried a legitimate sender might be caught by Outlook's spam filter, add them to Safe Senders instead of waiting for a problem.
What happens to blocked messages
When you block a sender, their messages don't disappear — they go to your Junk folder instead of your inbox. You can still read them if you check Junk, which is useful if you blocked someone by mistake or if you want to review what they sent before permanently deleting the messages.
Outlook does not delete blocked messages automatically. If you want them gone, you must open Junk, find the messages from that sender, and delete them yourself. Some people leave blocked messages in Junk for a while in case they need to reference them, then clean up later.
Blocked senders cannot tell they've been blocked. They see no error message, no notification, and no indication that you've blocked them. From their perspective, their messages are being sent normally — they straightforward don't know you're not reading them.
Frequently Asked Questions
Can I block someone on Outlook.com without opening their message?
No, you must open a message from that sender first. Click the three dots at the top of the message and select Block. If you want to block a sender you've never received mail from, you'll need to wait for their first message to arrive.
Does blocking a sender delete their old messages?
No, blocking only affects future messages. Messages you've already received stay in your inbox unless you delete them manually. If you want them gone, open your inbox, find the old messages, and delete them yourself.
What's the difference between blocking and marking as spam?
Blocking sends future messages to Junk automatically. Marking as spam does the same thing but also trains Outlook's filter to recognize similar messages as spam. For a single unwanted sender, blocking is simpler. For spam patterns, marking as spam helps Outlook learn.
Can I block emails by subject line or content?
Outlook does not have a built-in way to block by subject or content. You can only block by sender address or domain. If you receive many messages with the same subject from different senders, you may need to block each sender individually or use rules to move them to a folder.
If I block someone, will they know?
No, the blocked sender receives no notification. Their messages straightforward fail to reach your inbox. They have no way to know you've blocked them unless you tell them directly.