I can't seem to find this option available in Smartermail which I really need it to exists. I had set the outgoing mail size limit to 10MB for all domains but looks like when there is user sending out email larger than that, for example a 30MB email, Smartermail will still accept and let the 30MB email fully transferred into the spool, then only it'll bounce. This always causes the email to duplicate and jam up the whole spool.

 

Is there a way to make Smartermail remove/reject the email straight away from spool once the email reached 10MB without letting it grow larger than that?