Good afternoon. This question has been asked 5 or 6 times in this forum, but I don't believe it has ever been fully answered with a working solution. We just did some testing on this and it looks like there may not be a way to do what you are asking in Smartermail. However, you can use Declude content filters to accomplish this. If you don't already know, Declude is free anti-spam software that we offer on our website. You can download it here http://mailsbestfriend.com/downloads. You don't have to use it for spam filtering. You can simply configure it with the specific filters that you need to use without affecting anything else on your server. I hope this helps.

SmarterMail needs to allow filtering of outgoing mail. And, if it isn't already in current versions (I haven't checked), there should be a way to continue to the next filter condition even if the current filter condition is met.