Requirements: Stable Network connection & valid Fhi account
1. Start Thunderbird an "Create new e-mail account"
2. Select "Skip this and use my existing email"
3. Insert your Username@fhi-berlin.mpg.de and your username , and hit continue
4. Now select "Manual config", b'cause the outing mail server is wrong
5. Change the "Outgoing" server to "mail.fhi-berlin.mpg.de", then check your settings with "re-test"
6. You're done