Blocking Gmail, yahoo and hotmail is just dumb

[seiseki]

Luckily I could use http://meltmail.com/ to forward the email to my gmail.
But blocking the most common mail providers seems like a rather unorthodox and dumb way to prevent spam.

Especially since spammers can just do what I did, but most regular users won't have the knowledge, it's like the DRM equivalent for forums.