How to Block an Email Address in Outlook
Outlook gives you three overlapping ways to stop unwanted mail: the one-click Block button, the Junk email settings that hold your blocked list, and Sweep and rules for heavier automation. Which you reach for depends on whether you're swatting a single spammer, shutting out a whole domain, or taming a legitimate sender that emails too often. This guide walks through each, and the one limit worth knowing — the blocked list isn't infinite.
Block a sender from a message
These steps are for Outlook.com and the web app; the new Outlook for Windows and the mobile apps follow the same menu logic.
-
Select a message from the sender
Open
outlook.com, sign in, and click an email from the person or company you want to block. -
Open the message menu
Click the three-dot "More actions" menu at the top of the message (or right-click the message in the list). Look for Block in the menu that appears.
-
Choose "Block sender"
Select Block → Block sender. Outlook confirms, adds the address to your blocked list, and moves the current message to Junk. All future mail from that address is routed to Junk automatically.
The blocked senders list in Junk settings
Every address you block lives in one editable list. Going there directly lets you add senders you haven't received mail from yet, or tidy the list:
-
Open Junk email settings
Click the gear icon (Settings) → Mail → Junk email.
-
Add to Blocked senders and domains
Under Blocked senders and domains, click Add, type the full address, and save. You can also manage Safe senders here to make sure a wanted contact never lands in Junk.
Block a whole domain
To stop every address at a company or spam operation in one move, block the domain instead of individual senders. In Settings → Mail → Junk email → Blocked senders and domains, click Add and enter the domain with the @ sign, for example @example.com. Every message from any address ending in that domain is then treated as junk. Blocking a domain is powerful — it also catches senders there you might want, so reserve it for domains that are entirely spam.
Clean up existing mail with Sweep
Blocking only affects future mail. To deal with the backlog from a sender — or to set a standing cleanup rule — use Sweep:
-
Select a message and click Sweep
Tick a message from the sender, then click Sweep in the top toolbar.
-
Choose the cleanup rule
Options include Delete all messages from this sender, delete all and any future messages, keep the latest and delete the rest, or delete messages older than a chosen number of days. Confirm to apply it to existing and incoming mail.
Sweep is the better tool for a newsletter or notification sender you don't want to junk outright — it keeps your inbox clear without marking the sender as spam.
Rules for finer control
For anything Block and Sweep can't express, use rules. Go to Settings → Mail → Rules → Add new rule. Give it a name, set a condition (such as From a specific address or Subject includes certain words), and pick an action — Delete, Move to a folder, or Mark as junk. Rules run on incoming mail in order and can combine several conditions, making them ideal for routing or auto-deleting a specific stream of mail.
Limits of the blocked list
The Blocked senders and domains list holds a finite number of entries — historically around 500 addresses and domains combined. If you block one spammer at a time, a determined operation that rotates addresses will fill the list and outpace you. When that happens:
- Block the domain rather than each address — one entry covers them all.
- Use a rule to match a pattern in the subject or sender and delete on arrival.
- Prune the list of senders you no longer receive from to make room.
Blocking is the right response to a single persistent sender. When the flood comes from every direction, no blocked list keeps up — see our guide to stopping spam emails for the layered defense that does.
Frequently asked questions
Where does blocked mail go in Outlook?
When you block a sender in Outlook.com, their future messages are delivered to the Junk Email folder rather than the inbox. They are not rejected or bounced, and Junk mail is deleted automatically after a set period, typically 10 days for junk and 30 days for deleted items.
Can I block an entire domain in Outlook?
Yes. In Settings, open Mail then Junk email, and under Blocked senders and domains add the full domain such as @example.com. Every address at that domain is then treated as junk. Some organization-managed accounts restrict this option.
What is the difference between Sweep and blocking?
Blocking sends a sender's future mail to Junk. Sweep is a cleanup and automation tool that can delete or move all existing and incoming mail from a sender, or delete messages older than a chosen age. Use blocking for junk, Sweep to bulk-manage a legitimate but noisy sender.
Is there a limit to how many senders I can block in Outlook?
Yes. The blocked senders and domains list holds a finite number of entries, historically around 500 combined. Once full, remove old entries or switch to inbox rules or domain blocks, which cover many addresses with a single entry.
How do I unblock a sender in Outlook?
Go to Settings, then Mail, then Junk email. Find the address or domain under Blocked senders and domains and select the delete or trash icon next to it. Their mail then returns to the inbox on future sends.