The fastest way to block an email sender in Outlook

To block a sender in Outlook, right-click the email from that person and select Junk, then Block Sender. Outlook moves that message to your Junk folder and sends all future emails from that address to Junk automatically. The blocked sender cannot tell they have been blocked, and you will not receive notifications when they try to email you.

If you are using Outlook on the web (Outlook.com), the process is slightly different: open the email, click the three dots at the top right, select Junk, then Block. The result is the same — future emails land in Junk instead of your inbox.

On Outlook for Mac, right-click the message and choose Junk, then Add Sender to Blocked List. The blocked sender's emails go to your Junk folder from that point forward.

Key Takeaways

  • Right-click any email and select Junk > Block Sender to send that person's future messages to your Junk folder automatically.
  • Blocking works on the email address level, so if someone emails you from a different address, that new address is not blocked unless you block it separately.
  • You can view and unblock senders from your Outlook settings under Junk Email Options, where blocked senders appear on the Blocked Senders tab.
  • Blocking a sender does not delete emails already in your inbox — you must delete those manually if you want them gone.

Where to find your blocked senders list

In Outlook for Windows, go to Home > Junk > Junk Email Options. A window opens with four tabs: Safe Senders, Safe Recipients, Blocked Senders, and International Junk Email. Click the Blocked Senders tab to see everyone you have blocked.

In Outlook on the web, click the gear icon in the top right, then View all Outlook settings. Go to Mail > Junk email. Scroll down to the Blocked senders section to see your list.

On Outlook for Mac, click Outlook in the menu bar, then Preferences. Select Junk Email and click the Blocked Senders tab.

How to unblock a sender you blocked by mistake

Open your Junk Email Options (the steps above show you how to reach this screen on your device). Find the sender's address in the Blocked Senders list, click it to select it, then click Remove. Their emails will no longer go to Junk automatically.

Unblocking a sender does not move old emails out of your Junk folder. If you want to see messages they sent while they were blocked, you will need to go to your Junk folder and move them manually to your inbox or another folder.

Blocking a domain instead of a single email address

If you receive unwanted emails from multiple addresses at the same company or domain, you can block the entire domain. In Junk Email Options, go to the Blocked Senders tab and click Add. Type the domain name with an asterisk — for example, *@unwanteddomain.com — and click OK. All emails from any address at that domain will go to Junk.

Be careful with this approach if you have legitimate contacts at that domain. Once you block a domain, you will not see any emails from anyone at that company unless you unblock it or add specific people to your Safe Senders list.

The difference between blocking and other junk options

Outlook gives you three ways to handle unwanted email: block the sender, mark as junk, or delete. Blocking sends all future emails from that address to Junk automatically. Marking as junk tells Outlook that one specific email is junk, which helps train Outlook's filter but does not block the sender — future emails may still land in your inbox. Deleting removes the email but does not prevent future ones from arriving.

If you want to stop seeing emails from someone permanently, blocking is the right choice. If you just want to clean up your inbox and are not sure whether you will hear from them again, marking as junk is less permanent.

What happens after you block someone

Once you block a sender, their emails go to your Junk folder instead of your inbox. You can still see them if you open Junk, but they will not interrupt your day with notifications. If the sender tries to email you multiple times, all those messages pile up in Junk together.

Blocked senders do not receive any notification that they have been blocked. They will not know their emails are going to Junk — from their perspective, they sent the message normally. If they are trying to reach you and do not hear back, they may assume you are ignoring them or that the email did not go through.

Frequently Asked Questions

Can I block someone without opening their email?

No. You must open the email or at least select it in your inbox to access the block option. If you want to block a sender whose email you have not opened yet, click it once to select it, then right-click and choose Junk > Block Sender.

If I block someone, will they know?

No. Blocked senders receive no notification. Their emails simply go to your Junk folder instead of your inbox. They have no way to know you blocked them unless you tell them.

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

Blocking works on individual email addresses, not on people. If a blocked sender emails you from a different address, that new email will arrive in your inbox normally. You would need to block the new address separately if you want to stop seeing emails from it.

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

Outlook does not have a built-in feature to block by subject line or keyword. Your best option is to create a rule that automatically moves emails with certain words to Junk. Go to Home > Rules > Create Rule, then set the condition and action. This is more flexible than blocking but requires more setup.

Does blocking a sender delete emails already in my inbox?

No. Blocking only affects future emails. Messages already in your inbox stay there unless you delete them manually. If you want them gone, go to your inbox, select the emails from that sender, and delete them.