It appears that it is against policy for one of the sites that is feeding us referrals to send out transactional emails to customers that've used their 'gateway' (for lack of knowledge of a clearly defined better word in this instance).
Our site has been flagged by this aforementioned gateway due to our site sending out transactional emails to the address that is provided when they go through their referral process to our Magento instance.
At this point I don't have a whole lot of information on the best way to identify what transactional emails to filter.
I do have a domain that [all of the currently referenced] mail is allegedly being sent to (leading me to believe that the referral process from their end is substituting an email address that they're seeing this outflow from), and that might be one way to try to filter these emails, but I really don't know if that is the best way to try to go about this or not.
So I figured I would ask the experts. I believe SMTPPro is handling our 'transactional' emails, though I might be mistaken here.
Can anybody point me to a reference where I might find out a little bit better what subsystem, so to speak, is sending these emails (if indeed it is not SMTPPro), and how to go about selectively filtering what customers get an email sent and whatnot?
Any helpful information, or even pointers in the right direction, are greatly appreciated.