"Sending in background" with smtp_url

[Bertrand Janin <tamentis@xxxxxxxxxxxxx>]

Hello all,

The smtp server at work seems to be hanging randomly lately and after a
timeout mutt errors with "Could not send the message" followed by a
"Sending in background".

>From what I can see, I should only get this when using sendmail, not
when using smtp_url. When this happens I have to dig the email from
=sent and <Esc>E to resend it. Is there any way to avoid this from
happening (without setting up an MTA on my laptop)?

I am using mutt-1.5.19, the smtp server is using TLS on port 443.

Bertrand