Last month, my ip-addresses blocked by spamcop several times, but no spammers here.
It's because spammers send us email with wrong recipient addresses, and set Return-Path to spamcop traps.
I did hard work to change my network infrastructure of e-mail servers, add possibility to external MTA for checking local users on my internal MTA servers before receiving emails, and now, all attempts for sending emails on wrong recipients are fails on RCPT TO command, and no bounce message.
But now I wonder, because my ip-addresses are still blocked from morning, with "it will be delisted automatically in a short time".
What does this mean? Spamcop bug?