No Spam

Recently I put up a desktop installation of Postfix on a new FreeBSD boxen of mine. As alluded to in the previous entry, my ISP's SMTP relay was rejecting mail from this instance of Postfix.

As it turns out, if Postfix tries to deliver mail immediately, the ISP relay rejects them. But if I set SMTP as a "deferred transport" in Postfix so that the MTA first queues the mail, then the ISP relay accepts the mail when it gets delivered eventually. ;-/

I'm sure there is a logical explanation somewhere...