Frequently Asked Questions About Safe Attachments

What happens if I'm expecting an email and it has malware attached to it?

The message will be delivered but the attachment will not. The email message itself will see no changes whatsoever. Instead, the infected attachment will be deleted, and replaced with an attachment named ""Malware Alert Text.txt"". This attachment will read:

""The email attachment associated with this email was identified as an infected file. Action: the file(s) have been removed.""

Will email to me be delayed because of the attachment screening?

This protection will introduce some delay when it analyzes potentially harmful attachments. According to Microsoft, on average, email with attachments that need to be checked will be delayed by 4 minutes. Depending on the file type and size of the attachment, delivery may be delayed by up to 30 minutes. Email internal to Dartmouth (from one Dartmouth Office 365 user to another (e.g. accounts)) will not be analyzed, and will not experience any delays. Since the Dartmouth Computer Science department runs its own email server, extensive testing was performed sending emails with various attachments from the Computer Science mail server to Office 365 recipients. We did not see any noticeable delay and the ATP protections worked as expected. Many thanks to Wayne Cripps in Computer Science for assisting with this testing.

Can I get the email without delay, then get the attachment when it's done being analyzed?

Not at this time. The current process will not deliver the email message until the Safe Attachments service has scanned any attached files. Microsoft is planning to implement immediate delivery of just the email text in the near future. When that happens, the email will show a message that an attachment is currently being scanned. When the scanning is complete, if there is no malware found, the file will be attached to the email already in your mailbox. 

If I need a file, and can't wait for Safe Attachments to scan it, is there a way I can get it immediately?

The sender should put the file in a location where a link to that file can be shared (e.g. OneDrive), rather than emailing the file itself. Emailing the link rather than the file allows immediate access to the file without waiting for the Safe Attachments scan. 

What happens to the affected attachments?

Attachments containing malware will be deleted; all other attachments will be re-attached to the original email message and delivered.

What happens if an attachment is password-protected ?

Attachments that are password-protected cannot be opened by the Safe Attachments service so the attachment will be delivered.

Does the sender get notified that they're transmitting malware?

If the sending address was a account, the sender will be notified. Email sent from accounts will not receive a notification.

What if I forward my email to another email provider (gmail, hotmail, yahoo, etc.)? Will all mail sent to my Dartmouth address be subject to Safe Links and Safe Attachments even if I don't read it there? 

ATP will be implemented for all email sent to Dartmouth by accounts from domains other than """". Safe Attachments file blocking will apply to all email even if it is automatically forwarded. However, Safe Links will not be applied to email that is automatically forwarded to non """" accounts. This exception is made in order to optimize the delivery of automatically forwarded emails: Safe Links modifies the content of the email by rewriting the embedded URLs with a Safe Links URL, and this modification could cause problems with the delivery of email that is automatically forwarded. 

What if a faculty or staff member needs to receive an attachment that keeps getting deleted?

Dartmouth has a range of options available depending upon the size of the file, type of data, and security options required that will shape the recommended solution. In the rare circumstance that a legitimate file exchange gets interrupted by Microsoft's Advanced Threat Protection, contact the IT Help Desk at 603-646-2999 or via email at for assistance.

For more information see:

For additional questions, see IT Help Sources.


Article ID: 71537
Wed 2/6/19 8:30 AM
Mon 11/11/19 3:00 PM