Hi,
When an email is sent to an address and results in a hard bounce (mailbox/domain does not exist, rejected by Google groups, blocked by recipient spam filters/blacklisted, permanent failure, etc...) or if the recipient sent a complaint, this email address is added to a suppression list by Amazon SES (that our sending service uses).
The next time an email is sent to this address, Amazon will automatically block the sending of this email since it will result in a hard bounce.
If you don't want this message to show up anymore, you'll have to disable or delete the user concerned. Which is best practice anyway.
With the Enterprise level, if you enable automatic bounce handling these emails will be automatically handled, and subscribes will also be automatically disabled
.
Here is the bounce documentation:
https://docs.acymailing.com/main-pages/bounces/bounce-rules
https://docs.acymailing.com/setup/configuration/bounce-handling
Another way to keep your sending list clean is to use Acychecker: https://www.acychecker.com/
Are some of the email addresses that are in the suppression list valid (false positive)? Addresses can be removed from the suppression list, but this isn't available for our users, we need to do it manually on our side. For this you can raise a support ticket here: https://www.acymailing.com/support/
