This is related to revision
71f188082f
This is nice to have a meaningful explanation
for the user to understand why his mail is not sent,
this is better to not interrupt the mail queue when doing so.
Because of the above revision,
when the mail queue iterated on a mail failing because
of an ASCII encoding issue,
the mail queue was interrupted,
and on the next cron call it failed again and again
on the same mail, therefore leading to the mail queue
to never be processed.
Fixes#27804
Denis Ledoux
c41902a21c