In 2021, Gmail accounted for 36.5 percent of global email opens. As one of the most popular web-based mailbox providers (MBPs) in the world, it’s likely that they’re your go-to for email marketing. So, it stands to reason that the last thing you want is to end up on a Gmail blocklist.
A blocklist is a list of IP addresses and domains that have been reported as “known” sources of spam. Although blocklists exist to promote a safe and spam-free email environment, getting added to one can feel like the kiss of death for email marketers.
There are two main types of IP address blocklists: Real-time Blocklists (RBL) and Domain Name Server Blocklists (DNSBL). These blocklists are updated in real time and ISPs and MBPs use them to see if a sender has been flagged as a spammer.
Domain blocklists, like URI Real-time Blocklists (URI DNSBL), focus on domain names. MBPs use these blocklists to analyze and check for spam domains in the main message or body of an email.
We all know that blocklists can negatively impact inbox placement rates, but by how much? What blocklists are used by different MBPs? Here’s what you need to know if you’re sending emails to Gmail users.
Although Google doesn’t publicly disclose which blocklists they use, our data shows a correlation between Gmail and the following:
There are over 300 publicly available spam blocklists. However, not all of these blocklists are created equal when it comes to their impact on your deliverability. As a result, MBPs and other filtering companies will often use a combination of publicly available blocklist data and an internal blocklist to help determine whether or not to accept an email.
That said, these are the usual reasons why senders (good or bad) may find themselves on Gmail’s blocklist:
Spam complaints negatively impact your ability to land in a subscriber’s inbox. If Gmail accounts consistently mark your email as spam, your IP address may end up on a blocklist. To avoid this, ensure your email content is valuable, but above all, relevant to your subscribers.
Sending to spam traps is a symptom of poor list acquisition and list hygiene practices. To avoid this, regularly suppress unengaged Gmail accounts. Blocklists also use spam trap addresses—which are fake email addresses (pristine traps) or inactive (recycled, unused) email addresses—to determine the quality and accuracy of your email list, so keep it clean!
Speaking of which, poor list hygiene is important to avoid. Mailing lists can become increasingly inaccurate if companies have weak permissions and/or fail to observe opt-out requests. Follow consistent list management to avoid inaccurate mailing lists.
Sudden high-volume sending can also get you blocklisted if you have little to no established sender reputation. Avoid sending campaigns all at once or in quick succession if you’re sending from a new domain or IP address.
Misconfiguration of your email infrastructure—for example, if your reverse Domain Name System doesn’t match your SMTP—can also lead to being blocklisted.
Blocklist operators don’t necessarily want to blocklist legitimate senders, but their job is to protect email consumers from bad practices and fraud. If you’re not doing any of the following, you’re on a fast track to a blocklist near you.
This sounds obvious, but it needs to be said. When a legitimate sender gets listed, it’s because their campaigns have the characteristics of a spammer. Heed the advice above and you should have nothing to worry about.
Pro-Tip: Google has specific best practices for pulling emails from other accounts (otherwise known as redirects). Trying to circumvent them will only get you into trouble.
SPF (Senders Policy Framework) and DKIM (DomainKeys Identified Mail) are the two most widely used email authentication protocols. They help ensure email security and fight against spoofing. Aligning SPF and DKIM not only adds an extra layer of protection to your emails but also boosts your sender reputation.
Keeping good list hygiene is crucial, especially if you want to avoid getting spam complaints, bouncebacks, or sending to invalid or fraudulent email addresses.
These guidelines are for anyone who sends emails to Gmail users. If you’re sending a high volume of emails, following these guidelines will ensure your messages are sent. It will also lower the chances that Gmail blocks your messages or marks them as spam.
Be proactive about keeping your list clean by having subscribers opt-in at the point of acquiring their email, and again with a follow-up confirmation email.
Even good senders can end up on Gmail’s blocklist. If you’ve noticed a significant decrease in your email open rates, it’s time to figure out why.
If it turns out you’ve been put on Gmail’s blocklist, the first thing you should do is get to the root cause and address it. This is a key step before moving forward with a delisting request.
If you don’t take measures to fix and/or avoid making the same mistake, you’ll only get relisted, or worse––your request to be removed from said blocklist will be rejected.
Once you’ve gone over everything with a fine-tooth comb, you should be delisted within 3-5 days. If, after that, you still have issues with deliverability, it’s time to go ahead and make a formal request to Google through this form.
By this point, your responses to each prompt should be “No” (if any are “Yes”, Google will advise you to wait it out). Once you’ve sent the form, you should be delisted within a week.
Google doesn’t share any feedback in the above form or in response to your request. All you can do is monitor the situation and perform tests to see if your emails are getting through to the Gmail accounts in question.
Many blocklists have the option to request to be removed. If you’re looking to get delisted from Spamhaus, for example, simply head over to their lookup page and follow the instructions.
Equipped with the tools you need to understand blocklists, you can eliminate them as a foe and increase inbox placement at MBPs like Gmail.
To take your email program to the next level (and stay a step ahead of hungry competitors), check out our all-in-one Ultimate Email Marketing Toolkit for expert guidance to master email’s latest challenges.