Blacklist

A blacklist contains a list of IP addresses, domains, or email addresses that have deferred from the best practices of email delivery, achieved a poor sender score, and blocked from arrival into their intended inboxes.

ISPs use blacklists to protect their accounts from SPAM. This results in emails from known or regular offenders being blocked, keeping inboxes clean and tidy, and full of messages from purely respectable senders.

Some of the most critical email blacklists

  • CBL (Composite Blocking List)
  • Spamhaus
  • Spamcop
  • PSBL (Passive Spam Block List)
  • Invaluement
  • Barracuda
  • SenderScore
  • Frontbridge
  • SURBL

How to avoid getting yourself on a blacklist

If you follow cold email best practices, then you shouldn’t have anything to worry about. A sender would have to receive a high number of complaints or accrue a very low sender score to end up on a blacklist.

Here are a few of the most critical areas you should be monitoring:

  • Poor content considered to be SPAM - Whenever a recipient decides your emails aren’t what they signed up for and move them to their junk folder, and their ISP notified. When too many emails are reported as junk, sender scores drop, which adds to the chances of ending up on a blacklist.
  • Bad email addresses and high bounce rates - A high bounce rate will lower your sender score, and one of the worst offenders for those poor bounce rates are incorrect or inactive email addresses. Email addresses change all the time with users changing jobs or service providers; many of which remain on lists, upping their bounce rates.
  • Failing to provide an unsubscribe link - GDPR demands senders must now include an unsubscribe option. Without one, your emails could easily end up moved to junk or SPAM folders.
  • Low open rates - If your emails aren’t getting healthy open rates, then ISPs will think your content is irrelevant to the recipient and possibly SPAM.
  • Unnatural email list growth - ISPs will be wary of any sudden irregular growth of email lists. The usual reason for such growth is that a company has bought in a list as opposed to growing it organically.

Following best email marketing practices, monitoring your campaign data and results, and regular list cleaning will go a long way to keeping you out of trouble.

How do you get off a blacklist?

If you’re unfortunate to land on one of the many blacklists, getting yourself removed shouldn’t be too complicated a procedure.
Contact the provider to find out why you ended up on the list, and ask what you need to do to be removed.
Many of the major list operators will provide a simple step-by-step guide on their website.