Blocking a Sender in Outlook: Steps and What to Know

To block a sender in Outlook, select one of their messages and choose Block or Block Sender from the message’s menu. In Outlook on the web, you can also add an address or domain under Settings > Mail > Junk email; future mail from a blocked sender is generally routed to Junk Email, not prevented from being sent.

How blocking works in Outlook

Blocking tells Outlook to treat messages from a particular email address as unwanted. It is a filtering action on your mailbox: the sender is not notified, and Outlook does not stop the sender’s mail server from attempting delivery. Depending on the account and Outlook app, messages that match the blocked-sender list are sent to the Junk Email folder.

Blocking is useful when a person or organization keeps sending unwanted messages and you do not want to create a rule for every email. It is not the same as deleting a message, unsubscribing from a mailing list, or reporting a security threat. If a message is already in your Inbox when you block its sender, blocking does not necessarily remove that existing message. Delete or move it separately if you want to clear it out.

Outlook has several versions, and the menu labels can differ slightly between classic Outlook for Windows, new Outlook, Outlook for Mac, and Outlook on the web. The basic result is similar, but the location for managing the blocked list may depend on the app and the type of mailbox you use.

Block a sender in new Outlook or Outlook on the web

In new Outlook for Windows and Outlook on the web, use the message’s action menu. The precise placement of the menu can vary with window size, but the steps are usually:

Open Outlook and select a message from the sender you want to block. You do not need to open an attachment or follow a link in the message.
Select the three-dot More actions menu for that message.
Choose Block and then Block sender, if Outlook asks you to choose what to block.
Confirm the choice if a confirmation prompt appears.

You can also maintain the list directly in Outlook on the web: select Settings (the gear icon), then Mail > Junk email. Under Blocked senders and domains, add the complete address or domain and save the change. This is helpful when you know the address but do not have a recent message available.

Blocking a whole domain is broader than blocking one address. For example, blocking example.org can affect mail from multiple addresses at that domain, while blocking offers@example.org targets that particular address. Only block a domain if you are confident you do not need legitimate messages from other people or services that use it.

Block a sender in classic Outlook for Windows

In classic Outlook for Microsoft 365 on Windows, select a message from the sender, then go to Home > Junk > Block Sender. You can also right-click the message and look for Junk > Block Sender. If Outlook asks for confirmation, approve it. The sender is added to the blocked-senders list for the account or data file being used.

To review the list in classic Outlook, go to Home > Junk > Junk E-mail Options, and open the Blocked Senders tab. From there you can add or remove entries. If the message is in a shared mailbox or a different account, check which mailbox is active before assuming the block applies to your personal mailbox as well.

Classic Outlook and new Outlook are separate interfaces, and their settings are not always presented in the same place. If a sender you blocked in classic Outlook continues reaching your Inbox in another Outlook app, inspect the blocked list and junk-mail settings in that app or in Outlook on the web. Do not assume every local setting is automatically identical across all accounts and clients.

Block a sender in Outlook for Mac

In Outlook for Mac, select the message and look on the Home tab for the Junk menu or the block-sender action. Choose Block Sender if it is available. Menu names and placement can vary between Outlook for Mac releases, so updating Outlook or using Outlook on the web may be the simplest option if you cannot find the command.

For a Microsoft account mailbox, Outlook on the web provides a direct way to check the blocked list: open Settings > Mail > Junk email and review Blocked senders and domains. On a work or school account, an administrator may manage some mail-flow behavior, and the available controls can differ. If the Mac app’s action seems ineffective, verify the mailbox address and check the same account’s web settings rather than repeatedly blocking the message.

What happens after you block someone?

For future messages that match the blocked address or domain, Outlook will usually place them in Junk Email rather than show them in your Inbox. The sender does not receive a notice saying that you blocked them. The message may still be delivered to the mailbox and remain available in Junk Email until you delete it or the folder’s retention behavior removes it.

Blocking is not a guarantee that every message apparently from that person will be caught. Some unwanted senders change addresses frequently, and a message can display a familiar name while using a different underlying address. Conversely, a legitimate organization may send from different addresses for receipts, support, and marketing. Check the actual sender address before adding a broad domain to the blocked list.

Also remember that Outlook’s junk filtering and organizational rules can affect where mail goes. A company’s Microsoft 365 administrator may apply policies that you cannot change, and different mailbox providers may handle blocked-sender settings differently. If a blocked message still appears in the Inbox, examine the full sender address, the mailbox receiving it, and the relevant junk or rule settings.

Blocking, reporting, and unsubscribing are different

Choose the action that matches the problem. Blocking is useful for repeatedly unwanted mail from a specific sender. Reporting junk or phishing gives Outlook information about a message that appears unsolicited or deceptive. Unsubscribing is appropriate for a legitimate mailing list you knowingly signed up for and no longer want.

Block: filters future messages matching an address or domain in your mailbox.
Report junk: marks a message as unwanted and may help improve filtering. In Outlook, use the message’s Report or Junk option when available.
Report phishing: use this for messages attempting to steal passwords, payment details, or other sensitive information. Do not click the message’s links to unsubscribe.
Unsubscribe: use a trusted unsubscribe link in a genuine newsletter, or the built-in unsubscribe option Outlook may show for eligible bulk mail.

A common misconception is that blocking stops a company from emailing you altogether. It does not cancel a subscription, close an account, or remove your address from the sender’s mailing database. It changes how Outlook handles matching messages. For unwanted marketing, unsubscribe when the sender is legitimate; for suspicious mail, report it and avoid interacting with it.

Manage blocked senders and avoid false positives

Reviewing the list is worthwhile if you stop receiving an expected invoice, password reset, or appointment notice. In Outlook on the web, open Settings > Mail > Junk email and inspect the blocked entries. In classic Outlook for Windows, use Home > Junk > Junk E-mail Options > Blocked Senders. Remove an address or domain if it was added by mistake, then check Junk Email for messages that were filtered while it was blocked.

If a sender is safe and should reliably reach your Inbox, add the exact address to Safe senders and domains, where that option is available. This is usually safer than allowing an entire domain. A safe-sender entry can help with filtering, but it should not be used casually for unknown senders: it may reduce the protection provided by junk-mail filtering.

For a message that is already in Junk Email, use Not junk or move it to the Inbox, and consider adding the sender to safe senders if the mail is legitimate and expected. For a sender that changes addresses, blocking one address may not solve the problem; report the messages as junk or phishing as appropriate, and use provider-level or administrator controls if the issue is persistent.

Common problems and fixes

The message still arrives in the Inbox: compare the actual email address with the blocked entry. A display name is not enough; the sender may have used a different address or domain.
You blocked the wrong account: check the To field and the account selected in Outlook. A personal mailbox, work mailbox, and shared mailbox can have different settings.
The Block option is missing: open the message’s three-dot menu or check the Home or Junk ribbon. If the app does not expose the control, manage the list in Outlook on the web if your account supports it.
A legitimate message went to Junk: mark it as not junk, remove any mistaken blocked entry, and add the precise sender to safe senders if appropriate.
Blocking seems to have no effect: check whether an Inbox rule, organizational policy, or another mail client is changing the message’s location. For a work account, contact your Microsoft 365 administrator if the setting is controlled centrally.

When investigating, avoid forwarding suspicious messages to coworkers as ordinary attachments or replying to ask the sender to stop. For a suspected phishing attempt, use the reporting control provided by your organization or Outlook. If a message claims to come from a bank or service, visit that organization’s website by typing its known address yourself rather than clicking the email.

Frequently Asked Questions

Does blocking a sender in Outlook delete their old emails?
No. Blocking mainly affects how future matching messages are handled. Delete existing messages yourself, and check Junk Email if you want to review mail that was filtered after blocking.

Can a blocked sender tell that I blocked them?
Outlook does not send the person a notification that you blocked them. Their email system may still report that a message was sent, even though Outlook routes it to your Junk Email folder.

Can I block an entire email domain?
Yes, Outlook on the web lets you add a domain under Settings > Mail > Junk email > Blocked senders and domains. This can affect every address at that domain, so block an individual address instead when you only want to filter one sender.

Why do messages from a blocked sender still show up?
The sender may be using another address, the message may be going to a different mailbox, or a rule or organization policy may affect delivery. Check the full address and blocked list, then inspect the folder where the message landed.

Should I block or report a phishing email?
Report it as phishing rather than relying only on blocking. Phishers often rotate addresses, while reporting identifies the message as a security threat. Do not click links or open unexpected attachments in the email.

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