There are a couple things going on at darkclan.net that affect mail delivery to you. The more you know, etc.
Mail delivered to addresses hosted by us goes through a number of steps. First, the delivering host is checked against our firewall. The firewall, in a general sense, keeps portions of the Internet known to be spammer friendly from reaching us. The firewall also temporarily blocks out IP addresses of computers that appeared to attempt a break-in within the recent past.
The IP address is then compared to our mailer’s more specific list of IP addresses that have sent us viruses in the last Sunday to Sunday timeframe, and a more permanent set of pathological spammers and virus senders we’ve picked up on over time. The IP addresses are used only for this purpose. Any mail up to this point from blocked computers is wholly rejected; the only records are in our logs.
Mail then moves on to a virus scanning phase using ClamAV. Since we started using it, I’ve seen it make about five mistakes on legitimate mail. All mail recognized to be a virus is quarantined for us to either verify its illegitimacy or rectify the situation. All of the quarantined mail is archived for future research.
After this point, mail delivery depends on your particular domain. It may go straight to your account (or your forwarding address), or it may pass through a spam detection phase. We use SpamAssassin, a learning program that scores each piece of mail on how much it looks like spam. Individual configuration can either discard or quarantine marked spam; we tend towards keeping it all, too, since SpamAssassin’s recognition isn’t perfect.
If ever you think you’re not getting mail you want to receive, please let us know.