Blocked attachment types

Last updated on: 2021-07-05

This support document applies only to users who use the email system set up by MacWisdom Systems.

The following attachment types are frequently used by hackers to infect computers and to do harm. Because of that, they are rejected by the email system, and a "bounce" email will be sent back to the sender, letting them know the email was blocked and not received by the recipient.
Also, these attachment types may not be used in any email that is sent through the email system.

File type	Full file name
ade	Access Project Extension (Microsoft)
adp	Access Project (Microsoft)
app	Executable Application
asp	Active Server Page
vaspx	ASP.NET Web Page
asx	Advanced Stream Redirector
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
cnt	Index file for Windows help files
com	Command
cpl	Windows Control Panel Extension (Microsoft)
crt	Certificate File
csh	csh Script
der	X509 Certificate
exe	Executable File
fxpv	FoxPro Compiled Source (Microsoft)
gadget	Windows Vista gadget
hlp	Windows Help File
hpj	Microsoft Help Project File
hta	Hypertext Application
htc	HTML Component File
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
lib	Static DLL Library Information File
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)
mau	Access Shortcut Function
mav	Access View Shortcut (Microsoft)
maw	Access Data Access Page (Microsoft)
mda	Access Add-in MDA Access 2 Workgroup (Microsoft)
mdb	Access Application 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)
mht	Web Page Archive File
mhtml	Web Page Archive File
msh	3D Modeling File
msi	Windows Installer File (Microsoft)
msp	Windows Installer Patch
mst	Windows SDK Setup Transform Script
msh1	Microsoft Help File
msh2	Microsoft Help File
mshmxl	Microsoft Help File
msh1xml	Microsoft Help File
msh2xml	Microsoft Help File
ops	Office Profile Settings File
osd	Open Software Description File
pcd	Visual Test (Microsoft)
pif	Windows Program Information File (Microsoft)
plg	Aston Shell Plug-in
prf	Windows System File
prg	Program File
pst	Microsoft Exchange Address Book File, Outlook Personal Folder File (Microsoft)
reg	Registration Information or Key for Windows 95 or 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
sys	Windows System File
ps1	Windows PowerShell Script
ps1xm	Windows PowerShell Script
ps2	Windows PowerShell Script
ps2xml	Windows PowerShell Script
psc1	Windows PowerShell Script
psc2	Windows PowerShell Script
tmp	Temporary File/Folder
url	Internet Location
vb	VBScript File or Any Visual Basic Source
vbe	VBScript Encoded Script File
vbs	VBScript Script File Visual Basic for Applications Script
vpb	Visual Basic Project File
vsmacros	Visual Studio .NET Binary-based Macro Project (Microsoft)
vss	Visio Stencil (Microsoft)
vst	Visio Template (Microsoft)
vsw	Visio Workspace File (Microsoft)
vxd	Windows Virtual Device Driver
ws	Windows Script File
wsc	Windows Script Component
wsf	Windows Script File
wsh	Windows Script Host Settings File
xnk	Exchange Shortcut
xml	Extensible Markup Language