It’s not a friendly phrase, is it?

Well, that’s because it’s not a friendly place to be listed, especially if you are trying your hand at email marketing!

Being blacklisted can make anyone’s tea taste sour, but worse than that (yes there are worse things) it harms your deliverability more than a fair election on the Gaza Strip.

As an email marketer, you should know exactly what a blacklist is, how to avoid them and what happens when you find yourself on one – or you risk starting a war against people you can’t beat.

We’ve got you covered – ReturnPath went deep undercover to produce a study all about that dark section of the email marketing world – Email Blacklists.

The 3 Most Common Email Blacklists

It helps to know what the most commonly used email blacklists are in order to check if you are blacklisted, as some ISPs will not inform you.


  • Spamhaus refers to the combination of 4 different email blacklists that list both IP addresses as well as domains.
  • A typical offender usually stays on the Spamhaus list for only 1 to 2 days before getting themselves off. Usually the maximum amount of time you can expect to be on the list is about 6 days.
  • While Gmail does not explicitly state which email blacklists they rely on the most to identify spam, but the study implies that they most likely rely on spamhaus 82% of the time and CBL 4% of the time.
  • Unlike other email blacklists, most IPs and domains end up on Spamhaus’ email blacklist during the July period instead of the November to December period. However, it should be noted that July is still a holiday period where marketers adopt more aggressive sales tactics.


  • SpamCop tends to have a stable listing rate, consistently hitting 16% – 18% from Monday to Sunday and is only lists IPs.
  • While being one of the most consistent listors of spammers, IPs generally only remain on the list for 1 day or less.
  • This email blacklist sees the most activity during the Christmas Holiday period, seeing its peak of around 2000 IPs listed over November.
  • SpamCop has been operating since 1998 and has improved their service from feedback from users’ spam reports.


  • This email blacklist has the most listings over October, just before the holiday season.
  • 60% of IPs listed get removed from the email blacklist between 1 – 2 days, but 30% tend to only get off 7 days after first being listed.


They say what doesn’t kill you makes you stronger, but much like a wood chipper accident, it’s still so much better to avoid the situation in the first place!

Improving your deliverability is only the first step towards lightlistment, away from the darkside of blacklistment – but it is an important one. Here are some tips to get you started.

Remove Hard Bounces by Cleaning your List

You can do this the hard way by manually going through your reports, finding hard bounces and removing them (trust me, it’s even less fun than that it sounds) or you could forget about all that and leave the hard work to SharpSpring Mail +!

Subscribe to Feedback Loops

Subscribers who complain about your emails aren’t subscribers, they’re prisoners to your constant nagging – and they get plenty of that at home!

A lot of ISPs provide a system known as a feedback loop which lets you know which subscribers are complaining about your mail via a report – but they can’t send you this report if you don’t subscribe to their list (kind of ironic isn’t it?).

Don’t be a pest – remove people from your mailing list who complain about your mail, or get swatted onto an email blacklist!

Never Buy a Mailing List

If it’s too good to be true, it probably is, and if you still believe that bought lists can add some value to your email marketing campaign, then you’ve probably saved a couple Nigerian princes from a political coup.

Bought lists are full of old email addresses, hard bounces and people’s details which they did not intend to give up. Not to mention that buying a list is illegal in some countries!

Head Towards the White!

Now you can start turning your blacklist additions into whitelist applications! We recommend Certification.EQ from ReturnPath, as this covers a wide range of whitelists.

The best way to avoid the dangers of email blacklists is to use SharpSpring Mail +’s services and functionalities to their best!

Drop us a comment or contact us today to let us know how we can help you!


  • Author: maryka.burger

  • Maryka has worked across multiple industries ranging from hard news journalism to digital tech companies and advertising. She is an expert at building online presence, and offers a wealth of knowledge on digital marketing, social media and automation trends to agencies and digital start-ups.