'peer_terminated_conn' => # actual error differs FreedBSD vs. Linux
{ 'stderr' => 's/^( SMTP\()Connection reset by peer(\)<<)$/$1closed$2/' },
'peer_terminated_conn' => # actual error differs FreedBSD vs. Linux
{ 'stderr' => 's/^( SMTP\()Connection reset by peer(\)<<)$/$1closed$2/' },