Email Filtering

Viruses and Spam (unsolicited junk email) are two major issues facing email users. Thomas College takes proactive measures to protect users from both email based viruses and spam email messages.

Virus Blocking:

Our email servers are configured to scan all email messages coming through the system and block all incoming viruses that are attached to email. Any email carrying a virus is automatically rejected and discarded. Due to several common viruses that fake (or spoof) the source (or from) address of the sender, the sender and receiver are not notified that these messages have been discarded. Even though we block email-based viruses, we still recommend that users not open attachments from strangers, nor from people they even know if the attachment is not expected.

Attachment Blocking:

Our email servers are configured to block incoming attachments that are considered to be dangerous. These attachments are considered dangerous because they are actually scripts or programs that may contain a virus and should not generally be transfered using email. Though we update our virus protection signatures on a daily basis, we cannot rely 100% on our email virus scanning methods. This is because viruses must be released onto the internet before anti-virus software can be updated to detect it. This often leaves several hours or even days where the virus can infect users who are not protected. Because of this, we also block incoming email attachments that are considered dangerous. Users that need to send these types of attachments should rename the extension to a data file extension (.TXT for example) and include instructions for the recipient to change the file extension back to the original. For example, a user that needs to send a file called program.exe should rename the file as program.txt and explain to the user to change the filename back to program.exe in order to run the program.

Attachments that are blocked include:*.ad, *.ade, *.adp, *.asp, *.bas, *.bat, *.chm, *.cmd, *.com, *.cpl, *.crt, *.exe, *.hlp, *.hta, *.inf, *.ins, *.isp, *.js, *.jse, *.lnk, *.mdb, *.mde, *.msc, *.msi, *.msp, *.mst, *.pcd, *.pif, *.reg, *.scr, *.sct, *.shb, *.shs, *.url, *.vb, *.vbe, *.vbs, *.vsd, *.vss, *.vst, *.vsw, *.ws, *.wsc, *.wsf, *.wsh

Spam Filtering:

Our email servers are configured to filter out spam (unsolicited junk email) messages. Spam is much harder to stop then a virus and there are many different ways to attempt to filter spam. There is currently no 100% accurate method to block all spam, the technology for this does not yet exist. The spam blocking tool we use analyzes all incoming email and compares it with signatures of typical spam messages to determine if the message is likely to be spam. Using our spam blocking software, we expect the amount of spam filtered to be as high as 80 or 90%, but users should realize that current technologies will not block 100% of all spam messages.