CIS Department Wiki
Preventing unwanted email (spam or Junk Email) is a difficult problem. SPU has created a "defense in depth" for spam and has a dedicated filter appliance that helps reduce the problem significantly. Settings for the filter will affect all messages received by all SPU email accounts.
For those messages that make it beyond our server email filtering devices, Outlook 2013 has its own junk mail filter.
It is generally not a good idea to reply in any way to unsolicited commercial email since replying informs the sender that your email address is actively being used. Your address can then be put on a list of "verified" addresses and sold at a premium. Instead, just ignore and delete the email.
Better filtering will result in less spam, but it will increase the likelihood of individual messages being incorrectly routed to one of the holding areas for your review. By default, the Outlook 2013 Junk Email Filter will move email it considers Junk to the the Junk Email folder.
Since SPU maintains several layers of defense against spam, the more options you actively change, the more likely individual messages could be considered spam by your configuration.