>If submission rate limits are required, use SMTP instead of the Postfix sendmail command.
Aside from creating a "shim" of some sort to catch sendmail calls made by random malicious scripts and that uses SMTP to route mail to the local MTA, I don't see any solution. It's a bit above my paygrade since any and all MTA matters have a "cold water on neck effect" on me :-) By the way, thanks for the software.
