Good Day

I have a problem with MS Outlook 2003 and its junk mail filter. Our voice mail is recieved via a email message. The messages tend to go to junk mail, but on not messages.

I have changed the filter settings to low and updated it with the latest update from MS website, but some messages still go to the Junk Mail Folder. All the messages are exactly the same except for the From field were the telephone number is.

Could someone please assist me.