qmail-bfque: 451_unable_to_exec_qq_(#4.3.0) issue

[kp-org]

With qdkim the env var $QMAILQUEUE will be set to QMAILQUEUE="<path/to/>qmail-vdkim". If qmail-vdkim doesn't exists (what shouldn't be the default) the qmail-queue couldn't be executed.

Possible solutions:

1. check if the program in $QMAILQUEUE exists in 'qmail.c' and fall back to qmail-queue
2. rework qmail-bfque - the config file 'etc/beforequeue' have to be corrected similar to the one of qmail-bfrmt

If $QMAILQUEUE shouldn't be used to point to qmail-bfque only, so perhaps this could be done in 'qmail.c', like

• default: qq = qmail-queue
• if stat(qmail-bfque) --> qq = qmail-bfque
• if stat($QMAILQUEUE) --> qq = $QMAILQUEUE (overrides qmail-bfque)