Blocked Attachments in NUSmail

In NUSmail, there exist two layers of attachment type restriction, one of which is the blocking of attachments by Microsoft Outlook as well as the attachments that are blocked for incoming emails from the Internet.

Attachments blocked by Microsoft Outlook

For security, Outlook is designed to prevent you from opening up directly any unsafe attachments.

There has been frequent virus attacks in the past that have affected millions of people. Outlook has been updated to protect people from files, such as .exe and .bat files, that are often used to run malicious scripts when opened. This makes file sharing less convenient for many people, but security must take precedence.

Commonly used file types such as .doc, .xls, and .ppt files, are not blocked.

To send any of the following files, you can rename the files to include a temporary file type that is not on the list of blocked file types. For example, you might rename MyFile.exe to MyFile.exe_EXTRA and then attach the file to the e-mail message. You can include instructions in the message to save the file with the correct name, for example, MyFile.exe, when the recipients save the file to their computers.

Alternatively, zip up the attachment before you attach them to your e-mail message. In your message, you can include instructions explaining how to extract the files from the package to make it easy for recipients to access the files.

The following file types are blocked and cannot be accessed via Outlook.

File extension	File type
.ade	Microsoft Access project extension
.adp	Microsoft Access project
.app	FoxPro generated application
.bas	Microsoft Visual Basic class module
.bat	Batch file
.chm	Compiled HTML Help file
.cmd	Microsoft Windows NT Command Script
.com	Microsoft MS-DOS program
.cpl	Control Panel extension
.crt	Security certificate
.csh	Unix shell script
.exe	Program
.fxp	FoxPro file
.hlp	Help file
.hta	HTML program
.inf	Setup Information
.ins	Internet Naming Service
.isp	Internet Communication settings
.js	JScript file
.jse	Jscript Encoded Script file
.ksh	Unix shell script
.lnk	Shortcut
.mda	Microsoft Access add-in program
.mdb	Microsoft Access database
.mde	Microsoft Access MDE database
.mdt	Microsoft Access add-in data
.mdw	Microsoft Access workgroup information
.mdz	Microsoft Access wizard program
.msc	Microsoft Common Console Document
.msi	Microsoft Windows Installer package
.msp	Windows Installer patch
.mst	Visual Test source files
.ops	FoxPro file
.pcd	Photo CD image or Microsoft Visual Test compiled script
.pif	Shortcut to MS-DOS program
.prf	Outlook profile information (msrating.dll)
.prg	FoxPro program source file
.reg	Registration entries
.scf	Microsoft Windows Explorer command
.scr	Screen saver
.sct	Windows Script Component
.shb	Shortcut into a document
.shs	Shell Scrap Object
.url	Internet shortcut
.vb	VBScript file
.vbe	VBScript Encoded Script file
.vbs	VBScript file
.wsc	Windows Script Component
.wsf	Windows Script file
.wsh	Windows Script Host Settings file
.xsl	XML file that can contain script

Attachments that are blocked on incoming Internet mails

The following file types are blocked on all incoming mails from the Internet. They are not accessible even if they are plainly zipped. For such cases please advise the sender to password protect the zip files before sending it to you. Alternatively the sender may rename the file extension before sending it to you.

File extentions

*.wmf
*.bat
*.com
*.exe
*.hta
*.js
*.jse
*.lnk
*.pif
*.mdb
*.sct
*.vb
*.vbe
*.vbs
*.wsc
*.wsf
*.wsh
*.scr
*.cmd
*.cpl
*.job
*.<classid>

Macros embedded in word processing application files such as Microsoft Word and Excel.

Note: E-mails with Macros-embedded attachments will be detected as containing the GenericMac8_X97M virus. If that happens, please request the sender to re-send the attachment within a password-protected zip file.