Determining if a message is spam is based on a number of factors, including the "reputation" of the sender, the content of the message, other data that is sent along with the email message, quality and type of attachments, and the number of recipients.
Items may inadvertently be placed in your Junk E-Mail folder and treated like spam even though they may truly not be spam. Consider the following to options:
If the message comes from a person or company that should be trusted campus-wide, forward that message "as an attachment" to email@example.com. We will then work to get that person or company promoted into a trusted status.
If you trust the person or company but believe others may still consider the message junk, right-click on the message, choose Junk, and click Not Junk. You will be presented with a pop-up to Always trust e-mail from.... Check this box and press OK.