How to Block a Sender in the Outlook App on Any Device

To block someone in Outlook, open a message from them and use the Block sender option in the message menu; the exact menu depends on whether you use Outlook for Windows, Mac, the web, or a phone. Blocking moves future messages from that address to Junk Email rather than preventing the sender from sending them. Before you start, make sure you are signed in to the mailbox where you want the block to apply, and identify the sender’s actual email address.

Outlook’s menus can vary slightly with app updates and account type. The steps below cover the common Microsoft 365 versions and explain what to try when the option is not visible.

What You’ll Need

Access to the Outlook account that receives the unwanted messages.
An email from the sender, preferably one that has not been forwarded. A forwarded message may show the forwarder rather than the original sender in the message list.
A current version of Outlook or a web browser where you can sign in to Outlook on the web. If you use a work or school account, your organization may control some junk-mail settings.

Step-by-Step

Open the correct mailbox. Start Outlook and check the account name or profile so you are working in the mailbox receiving the mail. If Outlook contains several accounts, a block set for one mailbox may not affect the others. Find a recent message from the address you want to block. Do not open a link or attachment just to identify the sender; the message list or sender details are usually enough.
Check the sender’s full address. Display the message’s sender details if needed: click or tap the sender name to see the email address behind it. Names can be copied or imitated, and an unwanted sender may use more than one address. Blocking one address does not automatically block every address belonging to the same person or company. If the message appears to impersonate a trusted organization, treat it as possible phishing and use the report option rather than relying only on a block.
Block a sender in new Outlook for Windows. In the message list, right-click the message. Choose Block and then Block sender if Outlook shows a second choice. In some builds, the block action is available from the selected message’s toolbar or the … menu instead. Confirm the action if Outlook asks. If the menu does not include Block, use Outlook on the web for the same account and follow step 5, or add the address in Junk email settings.
Block a sender in classic Outlook for Windows. Select a message from the sender. On the ribbon, choose Home > Junk > Block Sender. You can also right-click the message and choose Junk > Block Sender. Confirm if prompted. If the message is already in Junk Email, you may need to select it there and use the same Junk menu. Classic Outlook may label the folder Junk E-mail in some installations.
Block a sender in Outlook on the web. Sign in to Outlook on the web or Outlook.com and open the message, or select it in the message list. Open the … menu for more actions and look for Block or Block sender. Confirm the choice. If that command is missing, open Settings (the gear icon), choose Mail > Junk email, and add the sender’s address under Blocked senders and domains. Choose Save if it appears.
Block a sender in Outlook for Mac. Select a message from the sender and look in the message menu or the message’s right-click menu for Block or Block Sender. Choose the command and confirm. Outlook for Mac’s menu wording and placement can differ by release. If the block command is not available, sign in to Outlook on the web with the same mailbox and add the address under Settings > Mail > Junk email > Blocked senders and domains. A web change is a practical alternative when the Mac app does not expose the setting.
Block a sender in the Outlook mobile app. Open a message from the sender, tap the … menu, and choose Report Junk if it is available. Select Block sender from the choices, then confirm. Some versions show a direct Block action instead, while others do not offer blocking for every account type. If you only see options to report junk or phishing, check the account’s settings in Outlook on the web; reporting and blocking are related but are not always the same action.
Check that the address was added. In Outlook on the web, revisit Settings > Mail > Junk email and look under Blocked senders and domains. In classic Outlook for Windows, open Home > Junk > Junk E-mail Options, then select the Blocked Senders tab. Do not add a broad domain unless you intend to send mail from every address at that domain to Junk Email. If you blocked the wrong address, remove it from the list and save the change.
Decide what to do with the message already received. Blocking normally affects incoming messages after the rule takes effect; it may not remove the message you used to create the block. Delete that message or move it to Junk Email if you do not want it in your inbox. If Outlook asks whether to report the message as junk as well as block the sender, choose based on what happened: report genuinely unwanted or deceptive mail, but avoid reporting a legitimate message sent in error.

Common Mistakes

Blocking the display name instead of the address. The visible name is not a reliable identifier. Check the full email address, especially when the message claims to come from a bank, delivery service, or colleague.
Expecting blocking to stop delivery entirely. Outlook usually routes messages from a blocked address to Junk Email. It does not stop the sender’s mail system from sending, and it may not stop notifications or messages from a different address.
Blocking a whole domain too broadly. Adding a domain such as example.com can affect legitimate messages from many people at that organization. Block the individual address unless you are sure you want all mail from that domain treated as junk.
Assuming every Outlook app has the same controls. Outlook’s Windows, Mac, web, and mobile menus differ. An option missing from the phone app may still be available in the account’s web settings.
Confusing block, junk, and phishing reports. Moving one message to Junk does not necessarily block its sender. Reporting phishing is intended for suspicious or deceptive mail; use a simple block for unwanted mail that is not a security threat.

Tips

Use the web settings as a reliable fallback. For Outlook.com and many Microsoft-hosted mailboxes, the blocked sender list under Settings > Mail > Junk email makes it easy to review, add, or remove addresses.
Check your Junk Email folder occasionally. A block can send future messages there rather than erase them. Review the folder for legitimate mail, and use Not junk or move the message back if Outlook catches something by mistake.
Use rules when you need a more specific outcome. For example, if you need to keep messages from a sender but separate them into a folder, create a rule rather than blocking the address. Rules are generally managed through Outlook’s Rules settings, and the exact options depend on the mailbox.
Be cautious with links to unsubscribe. For a legitimate mailing list, use its unsubscribe link or Outlook’s unsubscribe option when available. For suspicious messages, do not click links simply to stop them; report the message and block the sender instead.
Remember that spoofing can defeat a simple block. A spammer may change the address or imitate another sender. Report repeated abuse, use your organization’s security process for work mail, and adjust junk filtering if the problem continues.

Troubleshooting

I cannot find Block sender. First open or select an actual message, then check its … menu and the right-click menu. On classic Windows Outlook, use Home > Junk; on the web, use the blocked sender list in Junk email settings. Update Outlook if the interface is unusually old. Work or school administrators can restrict settings, so contact your IT team if the web list is unavailable or locked.

Messages still arrive in my inbox. Confirm that you blocked the exact address shown in the newest message, and make sure you blocked it in the mailbox that receives the mail. The sender may be using another address, or the block may not have synchronized yet. Check the blocked list, then allow a little time and test with a later message. If the sender changes addresses, block each one individually or report the messages as junk.

A legitimate email went to Junk. Open the message in Junk Email and select Not junk or move it to the Inbox. Then check the blocked sender list and remove the address if it was added by mistake. If the message is from a trusted organization using several addresses, removing a broad domain block may be necessary.

The blocked list does not match between apps. Outlook can connect to Microsoft, work or school, Gmail, Yahoo, and other mailboxes, and each provider may handle filtering differently. Confirm which account type you use and manage the block where that mailbox’s junk settings are stored. If a block created in one app does not appear in another, check the account’s webmail settings or ask your administrator whether the account uses a separate filtering policy.

I reported a message but did not block its sender. Reporting a message as junk or phishing may train filtering or send a report without adding a permanent block. Open the sender’s message menu again and choose Block sender, or add the address directly to the blocked list in settings.

Frequently Asked Questions

What happens when I block someone in Outlook?
New messages from the blocked address are generally delivered to Junk Email rather than your Inbox. The sender is not notified, and blocking does not prevent them from sending messages.

Can I block someone without opening their email?
Usually, yes. Select or right-click the message in the message list and use the Block option. You can also type the address into the blocked senders list in Outlook on the web without opening a message.

Will blocking an address delete old emails?
No. Blocking normally affects future mail, not messages already in your Inbox or other folders. Delete existing messages separately, and check Junk Email for later messages from that address.

Can a blocked sender tell that I blocked them?
Outlook does not normally send the person a notification that you blocked them. They may still send email, and their mail may be routed to your Junk Email folder.

How do I unblock a sender?
Open Settings > Mail > Junk email in Outlook on the web, find the address in Blocked senders and domains, remove it, and save. In classic Outlook for Windows, use Home > Junk > Junk E-mail Options > Blocked Senders and remove the address.

Does blocking one address block every address from that person?
No. Outlook blocks the address or domain you add, not every account a person may own. Add another address only if you want mail from that address sent to Junk Email too.

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