I've set up my WEB.DE account and double-checked my username and password, but I still get an error when trying to connect. Why?

Even with the correct credentials, WEB.DE requires you to explicitly enable IMAP (and POP3) access for your account before external applications like Unusual Suite can connect to it. This setting is not turned on by default.

Follow the instructions on the WEB.DE help page to enable IMAP access, then try connecting again.