optionally explicitly pass sendmail by environment variable and then fall back to guess by muttrc

[Konfekt]

For users having more than one mail account, how about an optional environment variable to set the sendmail command and only then fall back to guessing it by mutt -Q in

#  mutt/bin/mutt-ical.py (lines 147-149)
def sendmail():
    mutt_setting = subprocess.check_output(["mutt", "-Q", "sendmail"])
    return mutt_setting.strip().decode().split("=")[1].replace('"', '').split()

?