What is an email blocklist?
As the name suggests, an email blocklist is a list of email addresses (and IP addresses) that are automatically blocked by mail servers due to being flagged for spam.
If you want a more in-depth understanding of this topic, check out the FAQ section below:
Question #1: What is the difference between an email blocklist and an email blacklist?
There is no difference between an email blocklist and an email blacklist. Both terms refer to the exact same thing and therefore can be used interchangeably.
Question #2: How do I end up on an email blocklist?
In most cases, you end up on an email blocklist if you satisfy any of the following three criteria:
- You receive a lot of spam complaints
- A lot of the emails you send out end up bouncing
- Your email list suddenly experiences a massive growth
- Your emails have questionable or spam-like content
Let us take a look at each one in more detail:
The first and most direct way of ending up on an email blocklist is by receiving a lot of spam complaints. This is why if you want to do email marketing, you will need to make sure you get explicit permission from your recipients first before you start emailing them.
And if you want to be extra sure, you can also include a note in your emails telling your recipients why they are receiving emails from you.
Second, if a lot of the emails you send out end up bouncing, that may also be considered a red flag by internet service providers (ISPs). This is why some marketers ask each recipient to opt in a second time—usually by confirming their email address—before they actually add them to their email list. The goal is to eliminate (or at least significantly reduce) the number of invalid or unused email addresses that get through.
Third, another red flag that ISPs tend to watch out for is when an email list suddenly grows in size. Normally, such growth would happen slowly over time, so if a list of 5,000 people suddenly grows to 50,000 overnight, then there is a big chance that something suspicious has happened.
Finally, the content of your emails can also land you on an email blocklist. This is why using spammy words such as ‘make money’, ‘expect to earn’, and ‘online biz opportunity in your emails’ subject line is not a good idea—and so is using strange text formatting and a lot of consecutive exclamation points.
Question #3: How do I check if I am on an email blocklist?
The most straightforward way to check if you are on an email blocklist is by using free tools such as:
Keep in mind, however, that these tools will only check your IP address against publicly available email blocklists, so their results will not give you the complete picture. This is why you also need to monitor email stats. If you see a sudden drop in things such as your domain opens, for example, then it is possible that you are on some email blocklists.
Question #4: How do I get out of it?
To get out of an email blocklist, there are three things you can do, depending on the situation:
- Contact the blocklist owner for removal (if your IP address has been flagged)
- Fix the issues and wait for the block to sort itself out (if you have a relatively small email list)
- Check with your email provider what you can do, implement the fixes, and let your provider coordinate with the owners of the blocklists you are on (if you use an email provider)
Question #5: How does it work?
An email blocklist works by providing ISPs with something to check all incoming emails against. Whenever an ISP finds a sender’s email or IP address on a blocklist, it is automatically discarded.
But even if the sender passes this check, in most cases, the email they sent would still have to go through other spam checks first before it finally reaches the recipient’s inbox.