Composed emails are not sent


After the upgrade to K-9 Mail 5.800, when I’m sending an email, it is actually not sent. I don’t have any trace.

Note: I’m wondering whether this is related, but the “Save as draft” menu item is greyed out when I’m composing the mail.

The outgoing server uses STARTTLS, port 587, required sign-in, normal password, no client certificate.

When I revalidate the settings for the outgoing server, I can see that a connection is established in the logs of my server [TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256]. However, there are no logs when I send a mail, showing that K-9 Mail does nothing.