Wwitch forwarding address regarding the mail content.
It is simple if you can prepare different files as necessary.
For example, prepare
recipients.A
recipients.B
recipients.C
for the corresponding conditions A B C.
Set up the following hook:
if (condition A matched) {
$config->set('recipient_maps', "recipients.A");
}
elsif (condition B matched) {
$config->set('recipient_maps', "recipients.B");
}
elsif (condition C matched) {
$config->set('recipient_maps', "recipients.C");
}