The email system is setup to provide scanning for spam and viruses on all incoming emails.
Spam filtering is performed using a spam source list generated at http://www.spamhaus.org
in addition to one maintained by Mi-Co, Inc..
Virus scanning is provided by Clam-AV.

91124 messages rejected so far this week.
139868 messages rejected last week.
Current week data is updated typically on the hour.

All PCs connected to the internet need updated anti-virus software that scans everything that comes into the system.
This includes but is not limited to emails, attachments, and downloads via a web browser.