Hi,
suggestions did not fix the issue.
I further checked and found if outside sender sending mail to this group, the rule does not work. Inside sender mails sending to this group is ok.
if the outside sender sending directly to individianl mailbox, the mailflow rule will work.
It sounds if I like the rule working, I would like to inform outside partner send the mail one by one intead of send group.
brgds
Liu Wei