A computer virus is a program than can copy itself and infect a computer without the permission or knowledge of the owner. The term is often used as a catch-all phrase to refer to all types of malware, including computer viruses, worms, trojan horses, and other malicious and unwanted software. Viruses may cause harm to either a computer system's hosted data, functional performance, or networking throughput. Given the destructive nature of viruses, email entering the Texas A&M network will be scanned for viruses and rejected without being accepted or delivered locally.
All virus scanning companies will need time to construct a proper signature for a newly discovered virus though they all do respond fairly rapidly after a new threat is identified. Unfortunately, no scanning process is perfect and slight variances can cause the occasional message to slip by. The possibility of viruses reaching an end mail host or desktop without passing through the filter means that there is still a need to have virus scanning software on your desktop.
To make sure that the virus definitions on the SMTP relay machines are as up-to-date as possible, an automated process fetches a new list every five minutes.
The mail relays have the ability to detect suspected virus outbreaks. Messages that correspond to a suspected virus outbreak will be quarantined for 2 hours to allow anti-virus vendors time to issue a new signature. After 2 hours, suspect messages are re-scanned and, if no virus is found, the mesage is released to the original recipients.