I'm disappointed in how email and spam has been handled over the years by email applications. Today, if I would like to ensure that I receive one of the many email newsletters I subscribe to, the primary way to avoid having these messages marked as junk is to add the sender to my address book. I feel as if this is simply a stop-gap process that was put into place as email newsletters were getting their start in the mid-to-late 90's that has now become the norm. I subscribe to over 30 email newsletters, however, I have yet to actually email ANY of these newsletters and doubt that I would ever receive a reply from the newsletters' originating email addresses anyway (especially when so many of them have "no-reply" in their sending address).
So, bloating up my address-book with email addresses I'll never use has become the way to ensure that I receive my newsletters and can view them without having to "download images" and get them in my inbox vs. my junk email box. (And, instead of 470 contacts in my address book, I add another 30+ to ensure I get my subscribed emails. I know -- not a huge percentage, but still annoying to me.)
In my opinion, the ability to white-list email contacts to allow safe delivery from specific email addresses and domains and automatic image download (e.g. Outlook 2010 for Mac) versus adding that email as a contact would be very beneficial. I realize that the paradigm has always been to add a newsletter's originating email address as a contact to allow messages from that sender to come through properly, I just see that as a programatic FAIL, when just a simple whitelist feature would really simplify what shouldn't be a complex issue.