When setting up your computer or mobile device to access your IMAP email account, use the following settings:

Server Type: 
Incoming Server: imap.1and1.com
IMAP port with SSL enabled: 993

Outgoing Server (SMTP): smtp.1and1.com
SMTP port with SSL enabled: 587
Outgoing server (SMTP) requires authentication (same as incoming user name and password)

Account name/User name: Your full e-mail address
Password: Your e-mail account's password