If you are receiving a lot of stock tips spam, you can get rid of it by this method that I have explained on my forum. I have tried it myself and it works. Get rid of stock tips spam.
I don't think Charles Schwab sends spam, if you are on their mailing list, you can ask to be removed but it works for all those small companies that spam you with forged email address. Just for a day forward each email like I mentioned and in 1-2 days it will stop. I have tried it and it worked for me.
I'm not convinced it will work, on the principle that there's one more chump born every minute. So there will always be some other idiot paying spammers to talk up their worthless company. But maybe it can't hurt to do some education?