We do not allow executable attachments. In fact, there's a whole list of file extensions that are banned by our mail server, and we will simply not accept the message into the queue if one of them is detected.
This was a slightly controversial decision when we first made it back in 1999 but since then it has become common practice for most email providers to block potentially harmful attachments instead of relying on a virus scanner.
Note that we do NOT block document formats, even though these may contain macro viruses and other potentially harmful stuff. Neither do we block compressed archives such as .zip and .rar because these require user interaction before anything is executed. We do however rely on Norman Virus Control to block known viruses in these files.
Here is the full list of attachment types that we reject:- ade - Access Project Extension
- adp - Access Project file
- bas - BASIC program
- bat - DOS batch file script
- chm - Compiled HTML file
- cmd - 1st Reader External Command Menu
- com - Executable file (program)
- cpl - Control Panel Module
- crt - Certificate file
- emf - Enhanced Windows Metafile (Graphic format)
- eml - Outlook Express message
- exe - Executable file (program)
- hlp - Windows help file
- hta - HTML file
- inf - package information file
- ins - Install script
- isp - Sign-up file(X-Internet)
- jse - Javascript
- lnk - Shortcut file (Windows)
- mdb - Access database
- mde - Access file
- msc - Common console document (Windows 2000)
- msi - Installer program
- msp - Windows Installer patch file
- mst - Windows Installer transform
- pcd - P-Code compiled test scripts
- pif - Program information file (Win 3.1)
- reg - Registration file
- scr - Screen saver
- sct - FoxPro forms
- shs - Shell scrap file
- url - Internet shortcut file (Universal Resource locator)
- vbe - Visual Basic related
- vbs - Visual Basic program
- wsc - Windows Script
- wsf - Windows Script
- wsh - Windows Script