Just wondering if this is an intentional feature or if it is actually an unintended bug of Smartermail.
We have a very select few IP Ranges we have added to the Whitelist because for one reason or another they consistently triggered the Abuse Detection rules but were otherwise sources of 100% legitimate email. I have noticed after doing such that every day we have a large amount of emails sitting in the Delivery Queue for non-existent email addresses and sometimes non-existent domains. It would appear that if email is delivered from a Whitelisted IP, the recipient is not checked by Smartermail and it blindly accepts the message and then attempts to deliver to the non-existent account and continues to attempt redelivery until the max retries and then finally bounces the email with a Non-Deliverable Response. I understand that Whitelisting an IP Range should bypass all Spam Checks, but I didn't think that it would bypass checking whether that domain or email address exists or not.