Why do my newsletters end up in the bulk folder and how can I stop it?!?!?

I subscribe to a number of travel related newsletters online and for years they'd come to my inbox. Within about the last six months or so, they are going into my bulk folder, whereas the letters from the poor widow woman in parts far and distant who would like to give me millions of dollars in exchange for my banking information so she can deposit it directly come through daily. Does anyone have any suggestions on how I can again begin receiving my newsletters? Going through the bulk inbox is very tedious and I do have a job that I am rumored to be doing so that limits my time. I've called one of the travel companies and they resubscribed me and I'm still not getting the newsletters. Any and all help is much appreciated. NB: I have a popup blocker and have had it since day one so that may not be the issue...