How to Block an Email on Outlook (And What You Should Know First)
Unwanted emails are more than an annoyance — they can clutter your inbox, waste your time, and in some cases pose real security risks. Outlook gives you several ways to block senders, but the method that works best depends on which version of Outlook you're using and what you're actually trying to accomplish.
What "Blocking" Actually Does in Outlook
When you block a sender in Outlook, their messages are automatically moved to your Junk Email folder rather than your inbox. They aren't deleted outright — they're redirected. This matters because:
- The sender receives no notification that they've been blocked
- Emails still arrive at the server level; they're just filtered on your end
- You can review or recover messages from Junk Email at any time
- Blocking works per email address, not per domain (unless you configure it that way)
If you want emails from an entire domain to be blocked — for example, every address ending in @spamsite.com — Outlook supports that too, but it requires a slightly different step.
How to Block a Sender in Outlook on the Web (Outlook.com)
This applies to browser-based Outlook, including accounts accessed through outlook.com or Microsoft 365 via a web browser.
- Open the email from the sender you want to block
- Click the three-dot menu (More options) in the top-right corner of the message
- Select Block from the dropdown
- Confirm by clicking OK in the dialog box
The sender is immediately added to your Blocked Senders list, and all future emails from that address go straight to Junk.
To block an entire domain instead of a single address, go to Settings → Mail → Junk email and manually type the domain into the blocked senders field.
How to Block a Sender in the Outlook Desktop App (Windows)
The classic desktop application — part of Microsoft 365 or older standalone Office packages — handles blocking through the Junk Email options menu.
- Right-click the email in your inbox
- Hover over Junk
- Select Block Sender
That's it. Outlook adds the address to your Blocked Senders list and moves the current message to Junk immediately.
To manage your full blocked list, go to Home → Junk → Junk E-mail Options → Blocked Senders tab.
How to Block a Sender in Outlook on iPhone or Android 📱
The mobile Outlook app has a slightly more limited interface, but blocking is still available.
- Open the email from the sender
- Tap the three-dot menu in the top-right corner
- Select Block Sender
- Confirm your choice
Because the mobile app syncs with your account, the block applies across all devices where you're logged in — not just your phone.
Blocking vs. Other Filtering Options
Blocking a sender is one tool, but it's not always the right one. Here's how it compares to other Outlook filtering methods:
| Method | What It Does | Best For |
|---|---|---|
| Block Sender | Sends all future emails to Junk | Known spam or unwanted contacts |
| Junk Email Filter | Automatically catches suspicious mail | General spam protection |
| Rules | Custom routing based on criteria | Newsletters, work filters, sorting |
| Unsubscribe | Removes you from a mailing list | Legitimate marketing emails |
| Report as Phishing | Flags the message to Microsoft | Suspicious or malicious emails |
Blocking is most effective against a specific person or address sending repeated unwanted emails. For phishing attempts or malicious content, use the Report function instead — this helps Outlook's filters improve for everyone.
Variables That Affect How Blocking Works
🔍 A few factors change how this plays out in practice:
Which Outlook version you're using — The web app, desktop app, and mobile app all have slightly different interfaces. The underlying logic is the same, but the steps differ. Microsoft also updates its UI periodically, so menu locations may shift slightly from what's described here.
Your email account type — If you're using Outlook as a client for a Gmail, Yahoo, or IMAP account, blocking behavior may be handled by the external provider, not Outlook itself. In those cases, blocks configured in Outlook may not carry over if you access the same account elsewhere.
Exchange vs. personal accounts — Users on a corporate Microsoft Exchange or Microsoft 365 account may have IT-managed policies that affect junk filtering and blocking. Some organizations restrict what individuals can configure in their Junk settings.
How determined the sender is — Blocking a specific address won't stop someone from emailing you from a new address. Persistent spam often rotates through multiple sender addresses, which is why domain-level blocking and robust junk filters sometimes work better than blocking individual addresses one at a time.
Managing and Reviewing Your Blocked Senders List
Over time, your blocked list can grow long — especially if you've been using Outlook for years. Periodically reviewing it is worth doing because:
- An address you blocked may now belong to someone legitimate (email addresses get recycled)
- Overly aggressive blocking combined with a strict junk filter can occasionally catch wanted mail
- Removing old blocks keeps your list manageable and easier to audit
In the web app, your full list lives under Settings → Mail → Junk email → Blocked senders and domains. In the desktop app, it's under Junk E-mail Options → Blocked Senders.
Whether a simple one-click block is sufficient or whether you need to combine blocking with custom rules, domain filters, or IT-level controls depends entirely on your inbox situation, the type of account you're running, and how persistent the unwanted emails are.