Email trouble

[schaap]

I'm having trouble setting up the email service in cPanel. After I changed the dns servers at my registrar the site was working fine but I had to put it all back because mails were not coming in. I created a pop server but when I tried to send a mail to the email-account through the C panel webmail I got a socket error. Does anyone know what might have gone wrong?
Thnx

PS might it have anything to do with the crediting system? Is the crediting system setup to deny certain free hosting services when you don't have enough credits?