How to abort sending a mail?

[Max Görner]

Hello all,

I have a Mutt window open which hangs at the "Connection to ... establishing"¹
step. This happens very rarely but is quite annoying. In general, I am able to
send mails reliably and without issues.

My only known option is to kill `mutt`, which I dislike. Is there a better way
to abort that process?

Best, Max

1: Actually, it is "Verbindung zu subdomain.example.com wird aufgebaut …" but
    the above translation should do the job.