Email Blacklist Check: How to Avoid Getting Emails Blacklisted

Email marketers have a big fear of ending up on blacklists (with good reason too). Having email blacklist can result in a dramatic drop in deliverability of your emails and could cripple your entire email marketing program.
In this article, we’ll give you some best practices on reducing your chance of landing on a prominent blacklist.

How do blacklists work?

To begin with, it’s important to understand how blacklists work. Most blacklists use a so-called “spam trap”, email addresses that are used to identify where the spam mail is coming from, usually an IP address or a domain. If that IP address or domain does not check out, it is blacklisted.
Anyone can set up a blacklist for their own email server, and share the list for the public to use. Not all blacklists are created equal. Smaller blacklists, including SORBS and Spam Cannibal, have less influence with the bigger ISPs. Most large ISPs only use the most reputable blacklists like SpamCop, Spamhaus, and URIBL.
If a server gets on a blacklist such as SpamCop, any email from the server is blocked by ISPs that use the SpamCop blacklist. SpamCop and other reputable blacklists usually have a threshold, and usually, delist servers after a reasonable period of time.
For instance, you can use this blacklist check tool to check if your server is currently listed on any public blacklists.

How to make your email reach the inbox?

Despite the fact, that there’s no stop-gap solution, we suggest some best practices help your emails reach inboxes:
Confirm opt-ins: when you send a confirmation email before adding a new recipient to an active mailing list, only valid and engaged recipients will be added to your list. While this practice could potentially decrease the number of marketing email opt-ins for your list, the number of spam reports and unsubscribes will be reduced, which in the long run improves the ROI (return on investment) on each email sent. It also prevents all types of bad email addresses from being added to your list, reducing your hard bounce rates while increasing engagement rates. If you would rather not do double-opt ins, it’s best to have some other verification method (real-time or otherwise) to continuously clean your list.
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Validate addresses: checking for validity of the email address and common typos may help reduce friction, caused by confirming opt-ins. What is more, new signups are likely to react positively to this type of feature. There will be a reduction in common domain typos and instances of fake email addresses, resulting in fewer spam trap email addresses getting through to your list and ending up on a blacklist.
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Remove unengaged recipients: use a “sunset” policy, which means removing stale recipients based on engagement. You should remove email addresses if that recipient does not open or click a message in a certain period of time, which can vary depending on your industry and send frequency. While your mailing list size will decrease, your ROI per email sent will increase because you will only be communicating with engaged recipients. What is more, you will improve your sending and brand reputation because you don’t need to send emails to people who don’t want them.
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How to avoid being blacklisted

Here are some more easy-to-follow but effective suggestions to avoid being blacklisted:
  • Run your email through rigorous testing, including whether you’ve accidentally embedded a virus in it.
  • Review your data: check whether you have a disproportionate number of hard bounces to deliveries.
  • Always include an unsubscribe option in each and every email.
  • Check your email frequency: be careful not to scale back the number of emails you send per week.
  • Run your IP through blacklisting checkers to see if you’re already blacklisted.
  • Ask your subscribers to add your email address to their contact list (whitelisting).
  • Avoid using “spammy” words and phrases in any part of your email (especially in the subject line): free, win, check cashing services, get rich quick, opportunity. Make sure to also check out other tips on copywriting for better results.
  • Don’t ever use UPPERCASE for any words whether it’s in your subject line or body – those are flags for spamming as well.
  • Include options for your subscribers to view your email in an HTML or web-based version.
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  • Heath Weaver

    Managing Director, Principal

    Heath Weaver has almost two decades of eCommerce digital marketing experience. He has run multiple agencies, headed up Search Engine Marketing for the consumer electronics division of Sony, and served as a Vice President at Trilogy Software. He enjoys working day-to-day with clients to level up their retention marketing game.

  • Xiaohui "X" Wang

    Founder, Principal

    Xiaohui "X" Wang is a veteran of the email marketing industry. In the last decade, he has led the strategic and tactic retention marketing efforts for over 300 ecommerce brands ranging from small mom & pops to IR500 retailers. He's passionate about all things eCommerce, email, and SMS.