[solved] Thunderbird fails to sent emails

I have successfully setup Thunderbird mail client.

However, I cannot send emails.
This means, when composing an email, a copy is stored in the draft folder.
But when I try to send it, nothing happens.

I don’t think the issue is related to wrong SMTP settings, otherwise putting a copy in the draft folder should fail, too.

Can you please advise how to troubleshoot this issue?

(I cannot reproduce this issue with K-9 Mail client.)


Root cause identified.
Ticket can be closed.