suggests the use of IMAP over POP3. See why – >What does IMAP mean?
Server Type: IMAP Incoming Server: imap.1and1.co.uk IMAP port: 143 IMAP port with SSL enabled: 993 Outgoing Server (SMTP): auth.smtp.1and1.co.uk SMTP port: 25 or 587 Outgoing server (SMTP) requires authentication (user name and password) Optional: Secure SMTP encryption using TLS (using either port) Account name/User name: Your full 1&1 e-mail address Password: Your e-mail account’s password FOR POP3 PROTOCOL