Some attachment file types are blocked

Attachment Restrictions Explained

Our virus protection scans all inbound and outbound emails using a multi-stage process. The first stage of this process is through restricted attachments. Here, emails are scanned for dangerous types of file attachments. When an email is received that contains a restricted file attachment, the email is rejected and the sender receives a "bounced" email notification informing them of the restriction.

The following is a list of restricted attachments:

ade adp app
asp aspx asx
bas bat cer
chm cmd cnt
com cpl crt
csh der exe
fxp gadget hlp
hpj hta htc
inf ins isp
its js jse
ksh lib lnk
mad maf mag
mam maq mar
mas mat mau
mav maw mda
mdb mde mdt
mdw mdz msc
mht mhtml msh
msi msp mst
msh1 msh2 mshmxl
msh1xml msh2xml ops
osd pcd pif
plg prf prg
pst reg scf
scr sct shb
shs sys ps1
ps1xml ps2 ps2xml
psc1 psc2 tmp
url vb vbe
vbs vpb vsmacros
vss vst vsw
vxd ws wsc
wsf wsh xnk

Even if the message does not contain one of these restricted attachments, it will still be scanned at other stages for any potential viruses. If it is determined that the message did contain a virus, it will not be delivered. 

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