What type of hardware are you using: VPS bought online
What YunoHost version are you running: 12.0.11
What app is this about: gancio
Describe your issue
When I set up the email config in gancio (admin → e-mail-configuration), I put in smtp-hostname (mysubdomain.nohost.me), port (587), activate SMTP Secure, user (username), password (password) as described here Configuring email client | Yunohost Documentation . But it does not work, I get the following error.
I ran diagnose in yunohost and it showed up no problems in email.
Also I tried using sendmail, but it did not work. I received an gateway timed out error.
I am no expert so I am a little bit lost. I would be happy if someone could help me. 
Steffen
Share relevant logs or error messages
Error: 406CC5870D7F0000:error:0A00010B:SSL routines:ssl3_get_record:wrong version number:…/deps/openssl/openssl/ssl/record/ssl3_record.c:355: