Attachment file types blocked by Outlook

There are two levels of attachment security. Access to Level 1 files is blocked and can't be changed. When you receive an attachment with a Level 2 file type, you will be prompted to save the file to your hard disk. If you use Microsoft Exchange Server, your system administrator can add and remove file types for both levels of e-mail security. If a file type is added to both levels, it will be treated as a Level 1 file type.

Level 1

File extension File type
ade Access Project Extension (Microsoft)
adp Access Project (Microsoft)
app Executable Application
asp Active Server Page
bas BASIC Source Code
bat Batch Processing
cer Internet Security Certificate File
chm Compiled HTML Help
cmd DOS CP/M Command File, Command File for Windows NT
com Command
cpl Windows Control Panel Extension (Microsoft)
crt Certificate File
csh csh Script
exe Executable File
fxp FoxPro Compiled Source (Microsoft)
gadget Windows Vista gadget
hlp Windows Help File
hta Hypertext Application
inf Information or Setup File
ins IIS Internet Communications Settings (Microsoft)
isp IIS Internet Service Provider Settings (Microsoft)
its Internet Document Set, Internet Translation
js JavaScript Source Code
jse JScript Encoded Script File
ksh UNIX Shell Script
lnk Windows Shortcut File
mad Access Module Shortcut (Microsoft)
maf Access (Microsoft)
mag Access Diagram Shortcut (Microsoft)
mam Access Macro Shortcut (Microsoft)
maq Access Query Shortcut (Microsoft)
mar Access Report Shortcut (Microsoft)
mas Access Stored Procedures (Microsoft)
mat Access Table Shortcut (Microsoft)
mav Access View Shortcut (Microsoft)
maw Access Data Access Page (Microsoft)
mda Access Add-in (Microsoft), MDA Access 2 Workgroup (Microsoft)
mdb Access Application (Microsoft), MDB Access Database (Microsoft)
mde Access MDE Database File (Microsoft)
mdt Access Add-in Data (Microsoft)
mdw Access Workgroup Information (Microsoft)
mdz Access Wizard Template (Microsoft)
msc Microsoft Management Console Snap-in Control File (Microsoft)
msi Windows Installer File (Microsoft)
msp Windows Installer Patch
mst Windows SDK Setup Transform Script
ops Office Profile Settings File
pcd Visual Test (Microsoft)
pif Windows Program Information File (Microsoft)
prf Windows System File
prg Program File
pst MS Exchange Address Book File, Outlook Personal Folder File (Microsoft)
reg Registration Information/Key for W95/98, Registry Data File
scf Windows Explorer Command
scr Windows Screen Saver
sct Windows Script Component, Foxpro Screen (Microsoft)
shb Windows Shortcut into a Document
shs Shell Scrap Object File
tmp Temporary File/Folder
url Internet Location
vb VBScript File or Any VisualBasic Source
vbe VBScript Encoded Script File
vbs VBScript Script File, Visual Basic for Applications Script
vsmacros Visual Studio .NET Binary-based Macro Project (Microsoft)
vss Visio Stencil (Microsoft)
vst Visio Template (Microsoft)
vsw Visio Workspace File (Microsoft)
ws Windows Script File
wsc Windows Script Component
wsf Windows Script File
wsh Windows Script Host Settings File

Level 2

There are no Level 2 files by default. If you use Microsoft Exchange Server, your system administrator may add and remove Level 2 file types, or allow you to reduce a Level 1 file to Level 2.

Applies to:
Outlook 2003