GoDaddy
For almost half year of using their services I can't understand why they make life of customers so hard? They provide several servers for hosting, but the same hosting plan for different host servers works in many different ways. Firewall settings even different! For sending email they specified on the official page one server, but it doesn't work actually :). I've just discovered what server I should use to send messages via their smtp server. Good post here davidjsmitty blog