Chances are, you're reading this because you tried to sign up and the forum said your email address was banned.
It's not just YOU, it's all addresses at yahoo.com.
The problem is that Yahoo email is extremely easy to sign up for, in fact they have AUTOMATED scripts that will sign up for hundreds of email addresses at once, meaning that spammers can get hundreds of "disposable" addresses they can spam the living crap out of discussion forums with, without worrying about the address being banned, because they can come back tomorrow with a new one.
This problem has NOT YET reached other free mail services like Gmail, Hotmail, etc. so that's why THEY are not banned yet.
I've tried to lift the ban on *@yahoo.com before, and within 24 hours, the forum is flooded with spam. Therefore, the address shall be banned permanently.
Will this put off a few people from signing up? Probably. But since THEY aren't the ones that have to monitor, clean and maintain these forums - they should be a little more understanding.
And please - there is no need to email me with the old "I don't have any other email address to use - just Yahoo". We all know that isn't true. EVERY ISP on the planet offers at least ONE email address (usually 10-100 or more) accounts with every subscription of service. Sure, you might not use it often, because you like your web-based Yahoo.com mail - but that doesn't mean you don't have something else you can use.
I'm finding more and more sites that are refusing *@yahoo.com email addresses - so I don't quite feel so bad. Personally, I'm recommending GMail to all my friends and family - simply because they offer POP3, free forwarding, etc.
Anyway, I get tons of "my email address is banned" emails when on the sign up page there are like 800pt letters in RED saying we don't take Yahoo.com email addresses for sign ups. I figured maybe this post would help.