Block a Sender in Outlook Permanently: What Actually Works

To block a sender in Outlook and keep the block in place, add the sender’s email address to Outlook’s blocked senders list. Future messages that match it are normally sent to Junk Email, not stopped from being sent or automatically erased. The block remains until you remove it, but it cannot guarantee that a sender using a different address or a forged address will be caught.

Outlook has several versions, and their menus differ. The steps below cover Outlook on the web and new Outlook for Windows, classic Outlook for Windows, and Outlook for Mac. If you use a work or school account, your organization may manage spam settings centrally and restrict some options.

What You’ll Need

Access to the Outlook account where you want the block applied. Blocking in one personal or work account does not automatically block the same sender in your other accounts.
The sender’s exact email address, if possible. Check the message details rather than relying only on the display name, which can be misleading.
A web browser or Outlook app, and a moment to check that the address appears in the blocked list afterward.

Step-by-Step

Choose the Outlook account and version you use. Sign in to the mailbox that receives the unwanted messages. Outlook on the web and new Outlook for Windows have similar settings. Classic Outlook for Windows has a separate Junk E-mail Options dialog. On a Mac, settings names and locations can vary with the Outlook version, so use the blocked-sender settings where available.
Find the exact sender address. Open a message from the sender and look at the From details. In Outlook on the web, select or open the message and expand the sender information if needed to see the full address. In classic Outlook for Windows, open the message and inspect its From line. Avoid blocking a display name alone: several senders can use the same name, and a sender can change the name while keeping the same address.
Add the address in Outlook on the web or new Outlook for Windows. Select the Settings gear, then go to Mail > Junk email. Under Blocked senders and domains, select Add, enter the full address, and press Enter or choose the displayed add option. Select Save if Outlook shows a Save button. Reopen the setting and confirm the address is listed. Depending on the version, the setting may be labeled Blocked senders and domains or use slightly different wording.
Alternatively, block from a message in Outlook on the web or new Outlook. Select a message from the sender, then open the message’s More options menu, shown as three dots. Choose Block or Block sender, and confirm if prompted. The menu wording and location can change between versions. Afterward, check Mail > Junk email > Blocked senders and domains to make sure the address was added. If you cannot find a block command, use the settings method in the previous step.
Add the address in classic Outlook for Windows. Select a message from the sender. On the Home tab, choose Junk > Block Sender, then confirm the prompt. To verify or add the address manually, go to Home > Junk > Junk E-mail Options > Blocked Senders > Add. Type the full address, choose OK, and choose Apply or OK to close the dialog. Menu labels can differ slightly in older Outlook releases, but the Blocked Senders list is managed through Junk E-mail Options.
On Outlook for Mac, use the available block or junk controls and verify the list. Select the message and look for a Block Sender option in the message menu or the ribbon’s junk/report controls. Mac versions and account types do not all expose the same commands. If you do not see a block option, open Outlook settings and look for Junk Email or blocked-sender controls; add the full address if the list is available. If your version has no such list or control, use Outlook on the web for that same account, where the blocked-sender settings may be available.
Decide whether to block one address or a whole domain. Blocking a full address is usually the safer choice. In Outlook on the web or new Outlook, the Blocked senders and domains list may allow a domain entry such as example.com. That can route messages from every address at that domain to Junk Email, including legitimate ones. Do not enter a broad email provider’s domain unless you intend to affect all senders using it.
Check what happens to messages already received. Blocking generally affects future incoming messages; it does not reliably remove old messages from the Inbox or other folders. Search for the sender and delete or move earlier messages yourself if you want them gone. Check Junk Email as well: messages already there may remain there until you delete them or Outlook’s retention policy removes them.
Test the result without replying to the sender. Wait for the next message, if one arrives, and look in Junk Email. A message from the exact blocked address should normally be diverted there, though organization policies, filtering delays, or a different sending address can affect the result. Do not reply merely to test the block, since a reply confirms that your address is active.
Keep the entry in the list unless you want to unblock the sender. The list is the persistent part of the block. Revisit the blocked-sender settings occasionally to confirm the address remains listed. If you remove it, future messages from that address may go to your Inbox again unless another filter catches them.

Common Mistakes

Expecting the block to delete mail or stop delivery completely. Outlook’s blocked-sender feature is primarily a filtering control: matching mail is typically sent to Junk Email. It does not prevent the sender’s mail server from sending messages, and it does not necessarily erase mail already delivered. If you need a clean Inbox, check the Junk folder and delete messages separately.

Blocking the visible name instead of the address. A display name is not a reliable identifier. Check the full From address, especially if the message claims to come from a bank, delivery service, or colleague. If the address itself looks suspicious or impersonates a trusted organization, report the message as phishing rather than assuming that blocking the displayed name will protect you.

Blocking too much. A domain block affects many addresses at that domain, while an individual address block is narrower. Blocking a shared service, mailing-list provider, or common email domain can send wanted messages to Junk Email. Start with one exact address unless you have a clear reason to block every sender at a domain.

Using Block and Report phishing as if they were the same action. Block is intended to filter mail from a sender. Report phishing flags a message that appears designed to steal information or impersonate a trusted party. Use the reporting option when appropriate, and do not click links or attachments in a suspicious message. For ordinary unwanted promotions, use block or unsubscribe only when you trust the sender and the unsubscribe link is legitimate.

Assuming one Outlook account controls all your mail. Personal Outlook.com, Microsoft 365 work accounts, and other connected mailboxes may have separate settings. A block added in one account may not apply to another account shown in the same Outlook app. Confirm which account received the message before changing settings.

Tips

Use the narrowest block that solves the problem. If one address is sending unwanted mail, add that address rather than its entire domain. If a legitimate newsletter is the issue, use its unsubscribe link or the service’s preference settings when safe; blocking the sender may also divert useful account notices from the same address.

For persistent junk that rotates among many addresses, blocking each new address may not help for long. Use Outlook’s report-junk or report-phishing controls as appropriate, and review your organization’s spam reporting process if this is a work account. Do not open attachments or follow links just to identify the sender.

For a rule that handles a more specific pattern, such as a consistent subject line, create an Outlook rule in addition to blocking. Rules are not identical to a blocked-sender entry: they can move or delete matching messages based on criteria you choose, but a rule may miss messages when the sender changes those details. In Outlook on the web, rules are managed under Settings > Mail > Rules. In classic Outlook for Windows, use Home > Rules > Manage Rules & Alerts. Check the rule after creating it and make sure it applies to the correct account.

Keep an eye on Junk Email for a short time after blocking. If an important message from the same address lands there, mark it as not junk or remove the address from the blocked list. For a work or school mailbox, an administrator may have additional filtering that overrides or supplements your personal settings.

Troubleshooting

The sender is not listed after I used Block. Confirm that you selected the message in the account that received it and completed any confirmation prompt. In web and new Outlook, inspect Settings > Mail > Junk email > Blocked senders and domains. In classic Outlook for Windows, inspect Home > Junk > Junk E-mail Options > Blocked Senders. If the address is absent, add it manually. If the list is read-only or the setting is missing, your organization may control it.

Messages keep reaching the Inbox. Compare the new message’s full From address with the blocked entry. A near match, a different address, or a sender using a separate mailing service will not necessarily match the block. Add the exact address that sent the message. If the address is the same and the message still arrives in the Inbox, check for rules or organizational filtering that may affect handling, and report the issue to your Microsoft 365 administrator for a managed account.

The blocked message still appears in Junk Email. That is normally the intended result. Blocking routes matching messages to Junk rather than making them disappear. Delete the message if you do not need it, and check Junk Email periodically so that a legitimate message is not overlooked. Do not create an automatic permanent-delete rule unless you are comfortable losing messages that match it.

A wanted message is going to Junk. Remove the sender from the blocked list and mark the message as Not junk or Not spam, if that option appears. You can also add a trusted sender to the safe senders list where your Outlook version offers one. Safe-sender handling can vary by account and organization, so verify the result with a later message rather than assuming the change applies everywhere.

The sender uses a new address each time. An address block only matches the address or domain you entered; it cannot reliably identify every message from the same person or business. If the messages share a stable domain, consider blocking that domain only after weighing the risk of diverting wanted messages. Otherwise report the junk, use a carefully scoped rule for consistent message details, and ask your mail administrator about stronger filtering.

I cannot find the same menu shown in instructions. Outlook’s menus differ between classic Outlook, new Outlook, Outlook on the web, and Mac. Look for Settings > Mail > Junk email in the web or new interface, or Home > Junk in classic Windows Outlook. If the option is absent, try the web version for the same mailbox or check whether an administrator has disabled personal junk controls.

Frequently Asked Questions

Does blocking a sender in Outlook stop them from emailing me?
Not at the sending end. Outlook normally diverts messages that match the block to Junk Email. The sender may continue sending, and messages from a different address may not match.

Is an Outlook block permanent?
It stays in your blocked-sender list until you remove it, so it is persistent rather than time-limited. It is not an absolute guarantee against future mail because the sender can use another address, and mail filtering can vary by account.

Will the sender know I blocked them?
Outlook does not normally send the sender a notification that you blocked them. They can still send mail, so do not treat the block as a way to communicate that you do not want contact.

Can I block a whole domain?
Some Outlook versions let you add a domain to the blocked senders and domains list. This affects all addresses at that domain, not just one person. Use it only when you are sure you do not need legitimate mail from that domain.

Can I block a sender in Outlook on my phone?
Mobile app controls can vary by app version and account. If you do not see Block or a similar option in the message menu, open the same mailbox in Outlook on the web and add the address under Mail > Junk email. Verify that you are changing the account that receives the mail.

What is the difference between blocking and reporting phishing?
Blocking filters messages from an address. Reporting phishing sends a suspicious message through a reporting process and helps flag possible impersonation or credential theft. If a message is trying to trick you into sharing passwords or payment details, report it and avoid its links and attachments.

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