How to Block an Email Address in Outlook: Every Method Explained
A recruiter I'd never met started emailing me twice a day last month, using a slightly different address every time. By the fifth address, I'd stopped checking whether it was the same person and just hit Junk on autopilot. That habit almost cost me. A client's email got caught by the same filter that week, buried in the same Junk folder, and I nearly cleared it out unread.
Here's what nobody tells you about learning how to block an email address in Outlook: the button moves depending on which version of the app you're using, and blocking alone doesn't solve what most people expect it to.
I tested every current method, including a few buried in settings menus that most guides skip, and focused on which ones actually reduce inbox noise instead of chasing one sender at a time.
Quick reference: Every way to block an email address in Outlook
What blocking an email address does (and doesn't do)
Blocking a sender in Outlook adds their address to your Blocked Senders list. Every future message from that address gets routed straight to Junk Email instead of your inbox, though the message itself doesn't disappear.
It sits in Junk until Outlook clears it out, which happens 10 to 30 days after it arrives, or you delete it yourself.
Rules work differently. They're conditional automations: move this to a folder, delete it outright, forward it, flag it, all based on sender, subject, or keywords. Blocking is the simple, one-click option. Rules take more setup but give you far more control over what happens next.
Most people only need blocking, but rules give real control when a sender keeps finding a way back into your day.
How to block a sender on every version of Outlook
New Outlook, Outlook 365, and Outlook.com (Web)
- Open the email from the sender you want to block.
- Click the three-dot menu (More actions) at the top of the message.
- Select Block, then confirm Block sender.
- Future messages from that address now go straight to Junk Email.
You can also add someone without opening a message: go to Settings → Mail → Junk email, and under Blocked senders and domains, click Add, type the address, and save.
Classic Outlook for Windows (Outlook 2021 and earlier)
- Select a message from the sender in your inbox.
- Click Junk on the Home tab, then Block Sender. (Right-clicking the message and pointing to Junk works the same way.)
- Click OK to confirm.
The address is added to your Blocked Senders list immediately, and any existing messages from that sender move to Junk Email. Junk filtering needs to be turned on for this to route mail correctly. Check by going to Home → Block → Junk E-mail Options and confirming the filter isn't set to No Automatic Filtering.
Outlook for Mac
- Select a message from the sender you want to block.
- Click Block in the toolbar.
This only works for Exchange-type accounts: Outlook.com or a work/school account.
If you've connected a Gmail or Yahoo account to Outlook for Mac, the toolbar Block button won't apply, but you can still block from the Home tab under Junk → Block Sender.
Microsoft is retiring legacy Outlook for Mac in October 2026. If you're still on that version, blocking behavior may change depending on your Microsoft 365 license.
Outlook mobile app (iOS and Android)
- Open the message from the sender you want to block.
- Tap the three-dot menu.
- Tap Block Sender (on some app versions, this shows as Move to Junk, which has the same effect).
Mobile doesn't give you a way to view or edit your full Blocked Senders list. Sign in on the web or desktop app under Settings → Mail → Junk email for that. The list itself syncs across every device on your account, so blocking on your phone protects your inbox everywhere.
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How to block an entire domain
Blocking one address at a time is a losing game when someone keeps sending from a new address on the same domain. Instead:
- Go to Settings → Mail → Junk email.
- Click Add under Blocked senders and domains.
- Type the domain (for example, spamdomain.com) instead of a full address.
- Save.
Every message from that domain, regardless of the specific sender address, now routes to Junk. This works in New Outlook, Outlook.com, and Classic Outlook.
How to view, manage, and unblock senders
Everything you've blocked lives in one place: Settings → Mail → Junk email → Blocked senders and domains (Classic Outlook: Block → Junk E-mail Options → Blocked Senders tab).
Removing someone from the list unblocks them, and their next message lands back in your inbox normally.
Outlook currently allows up to 10,000 combined entries across your Blocked and Safe Senders lists, and Microsoft syncs only the first 1,024 entries on the Safe Senders side. Blocking domains instead of individual addresses stretches the list a lot further if you're bumping into that ceiling.
How to permanently block a sender in Outlook (using Rules)
Blocking is reactive, so you're always one step behind whoever's emailing you. Rules let you get ahead of it.
Right-click any message and select Rules → Create Rule (or Advanced actions → Create Rule on the web) to set Outlook up to automatically move, delete, or flag mail from that sender before it reaches your inbox.
Classic Outlook's File → Manage Rules & Alerts → New Rule gives more control, letting you combine conditions (sender, subject keywords, domain) with actions like permanent deletion or moving mail to a specific folder.
A rule that only watches your inbox will never see a message that junk filtering already pulled out. Build the rule to act on incoming mail directly if you want a sender's mail deleted outright instead of parked in Junk.
Try Lindy: Skip the manual sorting
Blocking clears out the senders you never want to hear from again. The bigger drain is everything in between: newsletters, notifications, and promotions nobody wants blocked outright but that still crowd out the emails that matter.
Lindy lives in Slack, and DMing it works like texting a personal assistant with access to your email, calendar, and a memory of what you've told it before. Give it a standing instruction once, in plain English, and it keeps sorting mail on its own from there.
- Set it once, in plain English: Tell Lindy to move newsletters out of your inbox, and it labels and archives them as they arrive.
- DM it like a person: Message Lindy in Slack, and it replies in your DMs. There's a web Home page too if you'd rather see everything in one view.
- Review before anything goes out: Replies and other actions stay in draft until you approve them.
- Alert you only when it matters: Set a rule like "only tell me about emails from clients" so urgent mail doesn't get lost in the sort.
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FAQs
1. Does blocking a sender in Outlook delete their emails?
No. Blocked mail moves to your Junk Email folder, not the trash. Outlook clears Junk on its own 10 to 30 days after mail arrives, but until then the messages are still there if you need to check one.
2. Can I block an entire domain in Outlook?
Yes. Add the domain instead of a specific address under Blocked senders and domains. It's the better move when someone keeps emailing from new addresses on the same domain.
3. Why is a blocked sender still getting through?
A few common causes: the sender is using a different address on the same domain (block the domain instead), the message was forwarded from another account, or the block hasn't finished syncing across devices yet. Checking the message headers for the sending address clears it up in most cases.
4. Does blocking work the same way on the Outlook mobile app?
Mostly, yes. Blocking or moving a message to Junk on mobile adds the sender to the same Blocked Senders list used everywhere else. You just can't view or manage the full list from the phone app itself.
5. What's the real difference between Block Sender and Rules?
Block Sender is a one-click way to send one address to Junk. Rules let you set conditions (sender, subject, keywords) and choose exactly what happens next, including permanent deletion or moving mail to a specific folder. Use blocking for one-off senders and rules for patterns.
