my %p = @_;
	$p{Sendmail} ||= "/usr/lib/sendmail";

	### Start with the command and basic args:
	my @cmd = ($p{Sendmail}, @{$p{BaseArgs} || ['-t', '-oi', '-oem']});

	### See if we are forcibly setting the sender:
	$p{SetSender} = 1 if defined($p{FromSender});

	### Add the -f argument, unless we're explicitly told NOT to:
	unless (exists($p{SetSender}) and !$p{SetSender}) {
	    my $from = $p{FromSender} || ($self->get('From'))[0];
	    if ($from) {
		my ($from_addr) = extract_addrs($from);
		push @cmd, "-f$from_addr"       if $from_addr;
	    }
	}

	### Open the command in a taint-safe fashion:
	my $pid = open SENDMAIL, "|-";
	defined($pid) or die "open of pipe failed: $!\n";
	if (!$pid) {    ### child
	    exec(@cmd) or die "can't exec $p{Sendmail}: $!\n";
	    ### NOTREACHED
	}