How to Block an Email in Outlook (Every Method)

How to Block an Email in Outlook (Desktop App)

Method 1: Block a Sender Directly

1. Open Outlook on your desktop
2. Right-click on an email from the sender you want to block
3. Select Junk → Block Sender
4. Click OK on the confirmation dialog

That sender's emails will now go straight to your Junk folder.

Method 2: Add to Blocked Senders List

1. Go to Home tab → Junk → Junk E-mail Options
2. Click the Blocked Senders tab
3. Click Add
4. Enter the email address or domain (e.g., @spammydomain.com)
5. Click OK

This method lets you block entire domains — useful when spam comes from multiple addresses at the same company.

Method 3: Create a Rule (Advanced)

For more control over what gets blocked:

1. Go to Home → Rules → Create Rule
2. Click Advanced Options
3. Set conditions (from specific sender, containing specific words, etc.)
4. Choose action: delete it, move to folder, or permanently delete
5. Name the rule and click Finish

Rules are more powerful than simple blocking — you can filter by subject line, keywords, attachment type, and more.

How to Block an Email in Outlook on the Web (Outlook.com / Microsoft 365)

Method 1: Block from an Email

1. Open Outlook.com or your Microsoft 365 webmail
2. Right-click on the unwanted email (or click the three dots ⋯)
3. Select Block → Block [sender name]
4. Confirm by clicking OK

Method 2: Settings Approach

1. Click the gear icon (⚙️) → View all Outlook settings
2. Go to Mail → Junk email
3. Under Blocked senders and domains, click + Add
4. Type the email address or domain
5. Click Save

Method 3: Report and Block

1. Select the unwanted email
2. Click Report in the toolbar
3. Choose Report phishing or Report junk
4. The sender is automatically blocked and Microsoft uses your report to improve filters

How to Block an Email in Outlook Mobile (iPhone & Android)

iPhone

1. Open the Outlook app
2. Open the unwanted email
3. Tap the three dots (⋯) in the top right
4. Scroll down and tap Block Sender or Report Junk
5. Confirm

Android

1. Open the Outlook app
2. Open the unwanted email
3. Tap the three dots (⋯)
4. Tap Report Junk or Block Sender
5. Confirm

Note: Mobile blocking options may be more limited than desktop. For full control, use the web or desktop version.

How to Block an Entire Domain in Outlook

If you're getting spam from multiple addresses at the same domain (e.g., sales@spamco.com, info@spamco.com, marketing@spamco.com), block the whole domain:

Desktop

1. Home → Junk → Junk E-mail Options → Blocked Senders tab
2. Click Add
3. Enter @spamco.com (include the @ symbol)
4. Click OK

Web

1. Settings → Mail → Junk email
2. Under Blocked senders and domains, click + Add
3. Enter spamco.com
4. Save

Every email from that domain will go straight to Junk.

How to Block Emails by Subject or Keyword

Sometimes you want to block emails containing specific words rather than from specific senders:

1. Go to Home → Rules → Manage Rules & Alerts
2. Click New Rule
3. Select "Apply rule on messages I receive"
4. Check "with specific words in the subject"
5. Enter the keywords you want to filter
6. Choose action: move to Junk, delete, or move to folder
7. Click Finish

This is useful for blocking:

• Newsletter topics you can't unsubscribe from
• Automated notification types
• Recurring promotional themes

How to Unblock a Sender in Outlook

Made a mistake? Here's how to unblock:

Desktop

1. Home → Junk → Junk E-mail Options
2. Blocked Senders tab
3. Select the address/domain → click Remove

Web

1. Settings → Mail → Junk email
2. Find the sender under Blocked senders and domains
3. Click the trash icon next to their name

Mobile

You'll need to use the desktop or web version to manage your blocked list — mobile doesn't have this option.

Outlook Safe Senders: The Opposite of Blocking

If important emails keep going to Junk, add the sender to your Safe Senders list:

1. Home → Junk → Junk E-mail Options
2. Safe Senders tab
3. Click Add and enter the email address or domain
4. Click OK

Emails from Safe Senders always go to your inbox, regardless of content.

Blocking vs Unsubscribing: Which Should You Use?

Rule of thumb: Unsubscribe from legitimate senders. Block everything else.

Why Emails Get Through Despite Blocking

Sometimes blocked senders still appear in your inbox. Common reasons:

1. Sender Uses Multiple Addresses

If you blocked john@company.com but they send from john.doe@company.com, it gets through. Solution: block the entire domain (@company.com).

2. Emails Routed Through Different Servers

Some senders use email marketing platforms that change the "from" address. Block the domain of the actual sender, not just the display name.

3. Outlook Rules Conflict

If you have rules that move emails to your inbox, they can override blocks. Check Rules → Manage Rules & Alerts for conflicts.

4. Junk Filter Set Too Low

Go to Junk → Junk E-mail Options → adjust the protection level. "High" catches more spam but may also catch legitimate emails.

5. Shared Mailbox Limitations

Blocks only apply to your personal mailbox. Shared or group mailboxes have separate junk settings managed by your IT admin.

Advanced: Using PowerShell to Block in Bulk (Microsoft 365 Admin)

If you're an admin managing Outlook for a team:

# Connect to Exchange Online
Connect-ExchangeOnline -UserPrincipalName admin@company.com

# Block a sender for the entire organization
New-TransportRule -Name "Block Spammer" `
  -FromAddressContainsWords "spammer@domain.com" `
  -DeleteMessage $true

# Block an entire domain
New-TransportRule -Name "Block Domain" `
  -SenderDomainIs "spamdomain.com" `
  -DeleteMessage $true

This is useful for blocking persistent spammers across your entire organization.

Protecting Your Own Emails From Being Blocked

If you're sending business emails and worried about being blocked by recipients, the problem is usually deliverability. Common reasons emails get blocked:

• Missing SPF, DKIM, or DMARC authentication
• Sending from a new domain without warming up
• High spam complaint rates
• Shared IP with bad reputation
• Triggering content filters

ColdRelay solves these problems with managed email infrastructure:

• Pre-configured authentication — SPF, DKIM, DMARC set up from day one
• Dedicated sending infrastructure — your reputation isn't shared with other senders
• Deliverability monitoring — know when there's an issue before it affects your outreach
• $1 per mailbox — scale your sending without scaling complexity

Getting blocked by recipients is the worst outcome for any email campaign. Start with infrastructure that keeps you in the inbox.

FAQ

Does blocking someone in Outlook notify them?

No. The sender has no idea they've been blocked. Their emails simply go to your Junk folder (or are deleted, depending on your settings).

Can I block emails on Outlook but not Gmail?

Blocking is per email client. Blocking someone in Outlook only affects your Outlook inbox. If you also use Gmail, you'd need to block them there separately.

Is there a limit to how many senders I can block in Outlook?

Outlook.com allows up to 1,024 addresses or domains in the blocked senders list. Desktop Outlook has a similar limit. If you're hitting this, consider domain-level blocking instead of individual addresses.

Do blocked emails count toward my storage?

Emails in Junk still count toward your mailbox storage. They're automatically deleted after 30 days in most Outlook configurations. If you want them gone immediately, create a rule that permanently deletes instead of moving to Junk.

Can I block all external emails in Outlook?

Not with the standard block feature, but you can create a rule. Enterprise admins can use Exchange transport rules to block all external email or restrict it to approved domains.

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Blocking unwanted email is defense. Having great deliverability is offense. ColdRelay makes sure your emails never get blocked — starting at $1/mailbox.