Blocking file attachments that are most commonly used to spread viruses will help protect University computer systems and data.  ITS uses the list that Microsoft uses for blocking attachments.  See Blocked attachments in Outlook - Outlook ( for the complete list. 

Messages containing these attachments may still be delivered but the file attachment is removed. You will receive an error message from Postmaster with the subject of "Undeliverable message"

This message was created automatically by mail delivery software. Your email message was not delivered as is to the intended recipients because malware was detected in one or more attachments included with it. All attachments were deleted.

--- Additional Information ---:

Subject: attachment test


Time received: 6/22/2017 5:14:09 PM

Message ID:<>

Detections found:

testing.docm     docm


All messages with an attachment that is considered safe (or that has no attached file) will be delivered intact. Office productivity files (documents, spreadsheets, etc), text files, and other files that are not executable programs will be delivered as usual.  

If a *.zip file contains a file with an extension (such as .EXE), which is in the list of suspect attachments above, the entire zip file is removed. 

Encrypted/Password Protected Attachments

If a file attachment is encrypted, or if it is password protected, and therefore cannot be examined for malicious code, the entire message including the attachment will be delivered (Examples are encrypted .zip files, and password protected office productivity files.)  No warning is given to the recipient that the file has not been scanned.


Article number: 
Last updated: 
November 8, 2021