The departmental mail servers use Clam Antivirus to scan all incoming/outgoing email messages. This includes scanning email bodies and attachments against known virus signatures as well as blocking certain MIME types and names (file extensions). The software will also scan compressed attachements.

Blocked MIME Types and Extensions

Certain MIME types and extensions pose a significant risk to windows machines, as they are executable by default. Most viruses are spread through email with one of these executable attachements. As such, the department has decided to block the following extensions: vbs, pif, scr, bat, com, exe, and dll. This means you will not be allowed to send/receive any filenames with the banned extensions. You can circumvent the block by compressing the file in either a .zip or .gz file.

Virus/Blocked Email Notification

The departmental mail servers will alert users when they receive or send an email containing a virus or banned content. Our servers do NOT reply to users outside the department when they receive an offending email, as this typically just adds to the spam epidemic.

Virus Notifications for Received Email

When one of our mail servers find a virus in an email destined for your email address, it will send you an email similar to

  VIRUS ALERT

  Our content checker found
      virus: Worm.SomeFool.Gen-1
  in an email to you
  
      from: someone@somewhere.com
      subject: check this out

  The message has been quarantined as:
      server: mailserver
      message: /var/lib/amavis/virusmails/virus-20040402-114545-03626-01

  This quarantined message will be saved for 30 days.  Please contact
  problem@cs.brown.edu with the above information, if you believe this is a
  valid message containing content you might want.

Blocked Notifications for Received Email

When one of our mail servers finds banned content in an email destined for your email address, it will send you an email similar to

  BANNED NAME ALERT

  Our content checker found
      banned name: blah.exe
  in an email to you
      from: mkd@cs.brown.edu
      subject: test bad

  The message has been quarantined:
      server: satern
      message: /var/lib/amavis/virusmails/virus-20040402-122144-04471-01

  This quarantined message will be saved for 30 days.  Please contact
  problem@cs.brown.edu with the above information, if you believe this is a
  valid message containing content you might want.

Virus Notifications for Sent Email

When one of our mail servers find a virus in an email you sent, it will send you an email similar to

  VIRUS ALERT

  Our content checker found
      virus: Worm.SomeFool.Gen-1
  in email presumably from you (<mkd@cs.brown.edu>), to the following recipient:
      -> someone@somewhere.com

  Please check your system for viruses, or email problem@cs.brown.edu
  for assistance.

  Delivery of the email was stopped!

As the warning message states, this email was NOT sent to the intended receipient.

Virus Notifications for Blocked Email

When one of our mail servers find banned content in an email you sent, it will send you an email similar to

  BANNED FILENAME ALERT
      
  Our content checker found
      banned name: blah.exe
  in email presumably from you (<mkd@cs.brown.edu>), to the following recipient:
  -> someone@somewhere.com

  Delivery of the email was stopped!

  The message has been blocked because it contains a component
  (as a MIME part or nested within) with declared name

Dealing with Virus Warnings

As the majority of the virus laden emails are really just spam, you might wish to filter them out of your INBOX. We have provided information about how to do so on our section on filtering.