Set up Apple Mail
Please open Apple Mail,
Click on Mail in the menu and then on Add Account.
Please select Other Mail Account ...
Please fill in the following window with your personal data and click on Register.
In the next window, please complete with the following information:
For the server for incoming e-mails, enter imap.oth-aw.de.
For the server for outgoing e-mails, enter smtp.oth-aw.de.
Click on Log in.
Complete the process by clicking on Done.