Unsafe File Types

Microsoft has deemed email attachments with certain extensions to be unsafe. The SSU email server filters unsafe attachments from messages, and a notice that the attachment has been removed is inserted in the message.

SSU email users have seen an increasing number of viruses that use email to spread. This problem is not expected to diminish in the near future.

If you need to send a file attachment with one of these extensions, you can rename the file so that it no longer has the original extension. In the message body you can include instructions for renaming the file back to its original name.

General Advice on File Attachments in Email Messages

  • If you receive a message with one of these unsafe attachments, don’t open the attachment. Delete the attachment.
  • If you receive any file attachment from someone you don’t know or if you know the person but are not expecting a file, don’t open the attachment.

Microsoft classifies the following extensions as unsafe.

Possible Unsafe Extensions

Microsoft Access project extension
Microsoft Access project
Microsoft Visual Basic class module
Batch file
Compiled HTML Help file
Microsoft Windows NT Command script
Microsoft MS-DOS program
Control Panel extension
Security certificate
Help file
HTML program
Setup Information
Internet Naming Service
Internet Communication settings
JScript file
Jscript Encoded Script file
Microsoft Access program
Microsoft Access MDE database
Microsoft Common Console document
Microsoft Windows Installer package
Microsoft Windows Installer patch
Microsoft Visual Test source files
Photo CD image, Microsoft Visual compiled script
Shortcut to MS-DOS program
Registration entries
Screen saver
Windows Script Component
Shell Scrap object
Shell Scrap object
Internet shortcut
VBScript file
VBScript Encoded script file
VBScript file
Windows Script Component
Windows Script file
Windows Script Host Settings file