The images used in this guide reflect iOS 5.1
Find and click Settings on your iDevice.
Scroll down and select Mail, Contacts, Calendars
Select Add Account…
Scroll down and select Other
Select Add Mail Account
Enter the name you wish to display to others when sending mail, your full e-mail address, and the password for the e-mail account. The description will mirror the e-mail address by default, although you may change it to whatever you like.
When finished, select Next at the top right.
Wait while the phone saves and then it should display a new screen with extra settings. Make sure that the IMAP button is selected at the top left and you should see the Name, Address, Description and Password should have carried over.
Scroll down and enter “imap.1and1.co.uk” without the quotes in the Host Name field and your full e-mail address in the User Name field under the Incoming Mail Server section.
Enter “auth.smtp.1and1.co.uk” without the quotes in the Host Name field and your full e-mail address in the User Name field under the Outgoing Mail Server section and enter the password for the e-mail account.
Then click Next at the top right.
If you receive a message that Cannot Connect Using SSL, click the Yes button to try without SSL.
Turn Mail syncing ON.
When finished, click the Save button.
The account should verify and you will be taken back to the main screen for Mail, Contacts, Calendars and see your newly set up account listed there.