Good idea, but blocking them, as has been stated, could lead to buying into something without knowing they are a PSC pump...some of the pumps don't have message board activity so you may not know...knowing which stocks are on the pumper email list can help tremendously with DD whether you want in for a quick flip or a slightly longer hold.
BUt I hear ya on the email thing...subscibe to one, and all of a sudden you get hit with 30. BUt again, it's good to have the knowledge...
Suggestion: open up a Yahoo email and have all the pump newsletters go there...that way, you won't be stressed when you open up your regular email and see 4,000 messages pumping crap like AVOE and MNTCF etc..
