I apologize if this has been posted before; I searched and can't find a definitive answer. 

I have been doing this for awhile now without any wins, and I've been very patient about it; however, I use Yahoo and I was recently told that some sweeps do not like Yahoo email addresses & will not accept them because they consider them "throw away" addresses, etc. 

I am contemplating moving my sweeping over to gmail or some other service but, before I make such a drastic move, I would really like to know if this is true.  I don't want to waste my time and go through the hassle if this is just speculation.  If it is true, how the heck do you go about switching to a new email without disqualifying yourself?

Thanks!