Troubleshoot Email Issues

If you're struggling to send emails especially from a self-hosted server or older email client; it might be because Port 25 is blocked on your connection.

This only applies if you're on our default CGNAT setup. We'll explain what that means and how to fix it.

We Block Port 25

Port 25 is the default port used to send email via SMTP.

However, it's often abused by spammers and malicious software.

To protect our network (and your inbox), we block Port 25 for most customers using CGNAT. This helps:

• Reduce spam and phishing risks

• Prevent your IP from being blacklisted

• Keep the network stable for everyone

This only affects you if you send emails using Port 25 with a self-hosted mail server, an email client set to Port 25, or automated tools sending mail from your network. If you use Gmail, Outlook.com, or other web-based email, you’re will not be affected.

Using Static IP

If you’ve upgraded to Static IP (our dedicated IP add-on), we don’t block any ports including Port 25.

You’ll have full control for things like self-hosting, remote access, and advanced configurations.

Learn more about Static IP

Fixes You Can Try

Use a different port

Change your email settings to use Port 587 or 465.

These are secure, supported alternatives for sending email.

Enable SMTP authentication

Check your provider’s settings.

Many email services allow sending with a username and password instead of using Port 25.

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Switch to a web-based email

Use Outlook.com, Gmail, or another browser-based service to send mail without issues.