Understanding Non-Existent and Suspended Bounces


Updated January 2020


Here at Constant Contact, we are an industry leader in email delivery. This is no accident. All of our Terms and Conditions are designed to ensure the best possible delivery rate. That being said, it’s expected that most email campaigns will have some level of bounces. Knowing the cause and reasons behind these bounces can help you as a marketer ensure you are mailing to the most current, engaged list that you can. Over the next few months, I will be writing about Constant Contact’s various bounce categories to (hopefully) clear up any questions you may have. In this post, I will be focusing on Non-Existent and Suspended Bounces.


What Are Non-Existent Bounces?


When Constant Contact tries to send an email to an address, it can bounce as Non-Existent if the receiving server tells us that the address in question does not exist.


For Example: Say I have the address “robbctct@example.com”, but I create a new email address and shut down this one. A few months later, if someone tries to send an email to my old address, “example.com” is going to send a message back to the sending server indicating that “robbctct@example.com” is no longer in existence.


What does Constant Contact do with email addresses that consistently bounce as Non-Existent? We “suspend” them.


What Are Suspended Bounces?


Put simply, they are email addresses that have continually bounced as Non-Existent.


Put not so simply, they are not true bounces. They are email addresses that have been placed on a global suppression list of addresses Constant Contact does not send to.


Allow me to explain. When an email bounces as Non-Existent, it is placed on a 15 day hold. During this time, no mail will go to the address in question from any Constant Contact account. After that 15 day period, mail will resume going to the address. If the address continues to bounce as Non-Existent, it will be added to Constant Contact’s global suppression list and show as a Suspended bounce within a bounce report.


Why Does Constant Contact Care About Bounces? (And Why Should You?)


Constant Contact is a “shared IP environment”, meaning that we have a number of IP addresses through which all customers send their mail. To ensure email delivery, we need to take measures to help the reputation of these IP addresses, otherwise ISPs and domains may decide to not accept our mail. Continually mailing to email addresses that bounce as non-existent is frowned upon in the industry and could impact Constant Contact’s ability to deliver your mail to the inbox.


You can help by managing your Non-Existent bounces after each campaign.


How Can I See My Non-Existent and Suspended Bounces?


If you look at the reporting for a specific campaign, click on the number of bounces you have. Then select “Non-Existent” or “Suspended” from the “All types” drop down.




What Should I Do If I Think A Non-Existent (or Suspended Bounce) Is Valid?


Here are a couple of reasons why a valid email address could be bouncing as Non-Existent:

  • There Is A Typo - Let's face it, nobody is perfect, and most people’s handwriting is certainly less than perfect. Typos happen, and often they can lead to bounced email addresses.
  • Bounce Coding - We classify bounces based on the information given to us by the receiving server. If the message received is too vague, or points to a Non-Existent bounce when it truly is not, then it could be erroneously categorized.

If you come across a Suspended bounce that you think is valid, you have the ability to unsuspend the contact in your account