What to do if your email is blacklisted

This guide explains how to tell if your email is being blocked by a blacklist (also called a blocklist), how to find out why, and what to do to get mail flowing again.

Signs your mail is being blocked

• Messages bounce back with words like “blocked”, “listed”, “rejected for policy reasons” or “poor reputation”.
• The bounce names a list, such as Spamhaus, Barracuda or SpamCop.
• People at one provider, such as Outlook.com or Gmail, stop getting your mail while everyone else still does.
• Mail you send ends up in recipients’ junk folders far more often than before.

Read the bounce message carefully. It usually says exactly which list, or which provider, refused the message. Keep a copy, as you will need it.

Check whether you are listed

Blocklists can list two things: the IP address of the server that sent the mail, or your domain name itself.

1. Find the sending IP. In cPanel, the General Information panel on the home page shows your account’s Shared IP Address. The bounce message often quotes the IP as well.
2. Visit a free blocklist checker, such as the MXToolbox blacklist check or the Spamhaus lookup page.
3. Enter the IP address and run the check. Then run it again with your domain name, such as yourdomain.co.uk.
4. Note any list that shows a match.

Being on one small, little used list is often harmless. A listing on Spamhaus, or a block from a big provider, is the kind that causes real problems.

Find the cause

A listing almost always means spam was sent, or appeared to be sent, from your account. The usual reasons are:

• A mailbox password was guessed or stolen. Spammers log in and send thousands of messages through it.
• A website form is being abused. An old contact form, or a form with no spam protection, can be used to send junk.
• A hacked website. Malicious code on a WordPress site can send mail on its own.
• Forwarding spam. A forwarder that passes spam on to Gmail or Outlook.com can make it look as if you sent it.

To see what has been going out, open Track Delivery in the Email section of cPanel. A sudden jump in sent mail, or messages to addresses you don’t recognise, points to the source.

Stop it and lock things down

1. Change the password of every email account on the domain, starting with any that showed odd activity. Use long, unique passwords. See how to change an email password or mailbox size.
2. Change your cPanel password, and turn on two factor sign in. See how to turn on two factor authentication in cPanel.
3. Update or remove any old form on your website. Add a CAPTCHA or similar check to forms you keep.
4. Scan the site for malicious code. See how to scan your site for malware and, for WordPress, how to clean a hacked WordPress site.
5. Check computers and phones that use the mailbox for viruses, in case the password was taken from one of them.

Don’t ask to be removed from a list until the spam has stopped. Most lists will list you again quickly if it carries on.

Set up SPF, DKIM and DMARC

These records prove to other servers that mail from your domain really comes from you. They won’t remove a listing, but they make your mail look trustworthy and make it harder for others to fake your address. See how to set up SPF, DKIM and DMARC.

Getting delisted

• The server IP is listed. Your account shares its IP with other customers, so we deal with this. Open a support ticket with the bounce message, the name of the list and the IP. Tell us what you have already changed.
• Your domain is listed. Once the cause is fixed, go to the list’s own website and follow its removal process. Most lists have a lookup page with a removal request link.
• A big provider is blocking you. Microsoft, Google and others run their own filters. Their bounce message usually links to a page explaining how to ask for a review. Send us the bounce in a ticket and we’ll check what we can do from the server side.

Some lists remove entries automatically after a period with no spam. Others need a request. We can’t control how long any list takes.

If it doesn’t work

• You are listed again soon after removal. The cause is still there. Check Track Delivery again and look for another mailbox or form.
• No list shows a match but mail still bounces. The problem may be something else. See why is my email not sending.
• Your mail goes to junk but isn’t bounced. See how to stop spam for the receiving side, and check your SPF, DKIM and DMARC records are correct.