Set Up E-mail with Mac OS X Mail using IMAP
For Mac OS 10.12.2
Follow these steps to configure the Apple Mail e-mail client for use with your 1&1 Mail Basic account using the IMAP Protocol.
E-mail clients like Apple Mail let you send and receive e-mails without accessing 1&1 WebMail.
Start Apple Mail.
Apple Mail Icon
If you have already set up an account in Apple Mail, click Mail > Add Account in the menu.
If you are using Apple Mail for the first time, you can skip this step.
Apple Mail Menu
In the Mail account provider window, choose the option Other Mail Account... and click Continue.
Mail Account Provider selection
The Add a Mail account window will appear.
Enter your name, e-mail address, and e-mail password. Then, click Sign In.
E-mail Account credentials
Enter your e-mail address in the User Name box (A).
Mail Server settings
Choose your desired account type. You can choose between the IMAP and POP account types (B). We recommend using the default setting - IMAP.
If you have chosen IMAP as the account type, enter imap.1and1.com in the Incoming Mail Server box (C). If you have chosen the POP3 account type, enter pop.1and1.com in the Incoming Mail Server box.
Enter smtp.1and1.com in the Outgoing Mail Server box (C).
Click Sign In.
If you receive the message "Username/password could not be verified," please check that your entries are correct.
Select the apps that you want to use with your mailbox and click Done.
In the Apple Mail menu bar, click Mail > Preferences.
Click Server settings.
In the Incoming Mail Server section, uncheck the box Automatically manage connection settings.
If you have chosen the IMAP account type, enter the port number 993 in the Port box in the Incoming Mail Server (IMAP) section.
If you have chosen the POP account type, enter the port number 990 in the Port box in the Incoming Mail Server (POP) section.
The TLS/SSL setting is recommended since it enables your e-mails to be encrypted with SSL when transmitted.
Apple Mail Accounts menu
In the Outgoing Mail Server (SMTP) section, uncheck the box Automatically manage connection settings.
Enter the port number 587 in the Port box in the Outgoing Mail Server (SMTP) section and click Save.
You are now finished setting up your mailbox.