How to Block Accounts from Sending Emails in WHM – Softsys Hosting

How to Block Accounts from Sending Emails in WHM – Softsys Hosting

If you're managing a cPanel server via WHM and want to prevent specific accounts from sending emails (e.g., due to abuse, spam, or policy violations), WHM provides a built-in way to restrict outbound email per user.

This guide explains how to block email-sending privileges for specific cPanel accounts on your Softsys Hosting VPS or Dedicated Server with WHM access.

📌 Requirements

• Root access to WHM on your server

• The server must be running Exim (default on cPanel/WHM)

🚫 Why Block Email Sending?

There are several reasons to block a cPanel user from sending mail:

• The account was compromised and is sending spam

• The website has outdated scripts vulnerable to abuse

• The client exceeds your email usage policy

• You are performing maintenance and want to temporarily halt email activity

🔧 Steps to Block Outgoing Email for a cPanel Account

1. Log in to WHM as root:
   👉 https://your-server-ip:2087/

2. In the search bar, type “Mail” and click on:
   Mail Delivery Reports (optional – use to confirm spam issues)

3. To block an account, go to:
   Home » Email » Mail Delivery Reports (for diagnostics)
   Then proceed to:

4. Navigate to:
   Home » Account Functions » Manage Account Suspension

   Or alternatively, use the Exim configuration below.

🛠️ Method: Use /etc/cpanel_exim_system_filter

For more control, you can add rules directly in the Exim system filter to block email sending from specific users.

Step 1: Edit Exim System Filter File

nano /etc/cpanel_exim_system_filter

Step 2: Add the Following Block Rule

Replace user_to_block with the actual cPanel username:

if first_delivery
and ("$authenticated_id" is "user_to_block")
then
  log_message = User user_to_block is not allowed to send emails
  seen finish
endif

Step 3: Save and Exit

🔁 Restart Exim

After updating the filter, restart Exim to apply changes:

/scripts/buildeximconf
service exim restart

✅ To Re-Enable Email Sending

Simply remove or comment out the blocking lines from the Exim filter, rebuild the Exim config, and restart the service.

🛡️ Best Practices

• Always inform the user before blocking, if possible.

• Use email throttling or limit settings as an alternative in:
  WHM » Tweak Settings » Mail

• Regularly monitor outgoing mail logs using:

  exigrep user@domain /var/log/