I'm having a problem with restricting my Plesk 8.0 server to ONLY accept mail from a single subnet and I'm curious if anyone has a suggestion for how to go about this. The reason why I need to do this is that I've purchased SPAM filtering services from mailroute.net for our entire server. Our MX record is changed to point to them and we are receiving mail through them without a problem. However, the issue is that spammers can simply ignore our MX record and go to the box directly; PSA-Qmail still happily accepts the mail. I've noticed that upwards of 60% of the SPAM we received after subscribing to their service did not go through mailroute.net indicating to me that spammers are still sending junk directly to the box. It's been more than six months since the MX switch so any TTLs and DNS caches should have WAY expired. I've tried placing the mailroute.net subnet into the mail server whitelist, but the box still accepts mail from anyone. I know this can be done directly through qmail. However, I'm always fearful of modifying anything from the command line without first consulting these forums. Not because I'm uncomfortable with manually editing the server, quite the contrary, I'm more concerned with angering Plesk. Are there any suggestions as to how I should go about doing this in a Plesk friendly way? Thanks.