How can I tell if I'm on a blocklist?

It's possible that you have landed on an ISP block list if you're seeing a large amount of soft bounces (anything over 5-10%) over an extended period of time,


Do not panic. Deliverability issues are (unfortunately) a normal part of the email marketing industry. You will not be blocked forever. We can help you solve this issue.


Currently the most common blocking issues are with Comcast, Cox, and Roadrunner. However, all ISPs have blocklists and given the right circumstances you can occasionally find yourself blocked.


Here's what to do if you think you are being blocked.


1.  Email


We know how to work with the major ISP's to resolve deliverability issues. Let us know if you think there's a problem and we will work on your behalf to solve it.


2.  Help stop this from happening again.


Here's where you come in. If you've landed on a block list there are generally four places to start looking for the solution:


List management 99% of the time this is the culprit. Make sure you are removing hard bounces, unsubscribes and abuse complaints right away. Do not send to hard bounces more than 2 times. When ISP's notice high hard bounce rates they will "flip the switch" and the rest of your emails will be blocked. You must maintain an extremely clean list if you want to avoid blocking issues. 
Infrastructure Do you have authentication (SPF / DKIM) set up correctly?  Most ISP's are looking for one or both of these. Make sure you have them and that they are set up correctly.
Sending Volume Are you sending 50 emails one day and 2 million the next? ISP's don't like that. ISP's monitor your volume carefully. Try to remain consistent with your sending habits. 
Email Content This isn't usually a problem but if you're using a lot of unusual characters or sending one large image you can run in to issues.





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