New Code
Postoffice has been rolled up to 1.0.7, because I got some spam from verizon and discovered, to my intense dismay, that verizon has instituted a callback mechanism to verify MAIL FROM:. If your mail server is like postoffice was before the lastest round of hackery, this would result in a 4xx error message, which verizon would incorrectly treat as a fatal error and thus, you couldn't send the thrice-damned abuse report. Normally I'd just bung the bastards into my blacklist alongside all the spamhouses and idiots who try to make you use some sort of stupid non-Lynx-compatable web-graphics-cgi opt-in web page before they'll accept your abuse report, but my little brother is on verizon and it's traditional to not reject mail from your family just because they're using some halfwitted net connection (I've already tried that trick, but my family is a lot more stubborn than I am.)
So, I changed the greylist to always accept MAIL FROM, but to return 4xx when a greylisted account does the DATA command. I'm waiting to see what the filthy scumsucking spammers think of to exploit this behavior.