unable to email with a scanned document attached to the email.

I have a 1315xi HP printer...I scanned my document and attempted to email it...it does not matter what email address I place within the "TO:" window a message appears that says, "The host '@yahoo.com' could not be found. Please verify that you have entered the server name correctly.
 Subject '', Account: 'POP3', Server: '@yahoo.com', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 11003, Error Number: 0x800CCC0D"

My questions are, #1, "who is my host &/or where do I go to find out who he/it is?"; #2, "Where would I find out who my server name is?";

Bob