At IU, what types of attachments are blocked from my email account?

To protect computers at Indiana University, UITS has enabled filters for attachments that have been known to carry viruses.

If you know your file is safe and need to share it, you can rename the file, using either a different extension or no extension, and then attach it to your email message; see At IU, how can I send email with a blocked attachment type? Alternatively, you can share the file using one of IU's file-sharing services, such as Box or Slashtmp; see At IU, how can I collaborate on documents and share data with others?

The UITS attachment filters block the following file types:

  .ade
  .adp
  .app
  .asp
  .bas
  .bat
  .chm
  .cmd
  .com
  .cpl
  .crt
  .csh
  .exe
  .fxp
  .hlp
  .hta
  .htr
  .inf
  .ins
  .isp
  .jar
  .js
  .jse
  .ksh
  .lnk
  .mda
  .mdb
  .mde
  .mdt
  .mdw
  .mdz
  .msc
  .msi
  .msp
  .mst
  .ops
  .pcd
  .pif
  .prf
  .prg
  .reg
  .scf
  .scr
  .sct
  .shb
  .shs
  .url
  .vb
  .vbe
  .vbs
  .wsc
  .wsf
  .wsh

Archive files (e.g., zip or tar files) that contain any of the above file types will also be blocked.

IU Exchange accounts

Microsoft Exchange's anti-malware protection strips blocked files from messages leaving the IU Exchange system and delivers the messages to recipients without the attachments. If someone from outside the IU Exchange environment sends a message containing one of the blocked attachment types to your Exchange account, you will not receive the attachment or the message. The filtering software at the external mail relays blocks the entire message, and will generate a nondeliverable response (NDR) message to the sender. However, it's up to the sender's email system to accept NDRs. Because of the amount of NDR traffic that spam and viruses cause, many systems do not accept NDRs.

If you send a message from an Exchange account with a .shb, .shs, .vbs, .com, .exe, .pif, or .scr attachment, you will receive a "Non delivery report" message (a "bounce") stating:

Delivery has failed to these recipients or groups:

[List of recipients]

Invalid file extension on attachment

Your message wasn't delivered due to an e-mail rule restriction created by the recipient's organization e-mail administrator. Because viruses or malicious scripts can be easily distributed in executables, scripts, and compressed files, the IU Exchange servers will delete the email if a blocked attachment is detected, in order to protect our users. For a list of blocked attachments, please see the IU KB document "At IU, what types of attachments are blocked from my email account?" (https://kb.iu.edu/d/ajch)

If you were not aware that you sent an attachment, then it is possible that your computer is infected with a virus. Contact your technical support provider; if you are affiliated with Indiana University, please see "How do I contact the Support Center at each IU campus for help?" (https://kb.iu.edu/d/abxl) For more information, please see "What should I do if I receive a computer virus alert message via email?" (https://kb.iu.edu/d/adbm)

Details such as original message headers will appear under the heading "Diagnostic information for administrators".

This is document ajch in the Knowledge Base.
Last modified on 2015-07-17.

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