What, specifically, do you do to prevent spam and virii from reaching our mail boxes?
All incoming mail is checked and tagged using Spamassassin and MailScanner/ClamAV antivirus. We do not delete spam, just tag it in a way that let you easily sort the mail directly on the server using a procmail script or in an email client such as Outlook. Any known virus detected by ClamAV are removed and the mail forwarded with a notice.