"No account" on sending window

I think I’ve set correctly my IMAP account. I receive all the emails, but when I try to compose a new message I can’t select any account and the button on the right of “Send” says “No account”.
My account settings look like this

I can’t find any options that help me, and diagnostic seems not to find any error.

The account is not setup correctly.

Probably during autodiscovery the server did not offer any SMTP (sending) protocol, so it was not added as a service. You will need to remove the account, then set it up manually. You can find full instructions for manual setup in the Documentation (F1) under Getting Started.