I've seen a lot of people with problems in setting up Road Runner emails on Samsung Moment by Sprint. Here is the thing:
Incoming Server Settings:
Usarname:
XXXX@wi.rr.com (In my case, I am located in WI)
Password: XXXX
POP3 server: pop-server.wi.rr.com
Port: 110
Security Type: None
Delete email from server: When I delete from Inbox
Outgoing server Settings:
SMTP server: smtp-server.wi.rr.com
Port: 25
Require sign-in (Checked)
username: Your email address
Password: XXXX
I hope it helps.