Hello Flakko,
This is usually caused by a wrong Freenet server name, an expired provider certificate, or the phone not trusting the certificate.
Please check these settings in Aqua Mail:
Incoming IMAP server: mx.freenet.de
Port: 993
Security: SSL/TLS, strict certificate check
Username: full Freenet email address
Outgoing SMTP server: mx.freenet.de
Port: 587
Security: STARTTLS, strict certificate check
Authentication: enabled
Also check on the phone:
Date and time set to automatic
Aqua Mail updated to the latest version
Try Wi-Fi and mobile data
If it started only a few days ago and your settings are already correct, it may be a Freenet certificate/server issue. In that case, please try again later or check if Freenet webmail works.
