We are using Lotus Domino 8.5.3 FP6. We have around 100+ local groups defined for email circulation purposes like DEPT1 , DEPT2 or so on & added respective users in it . When any user from the internet sends email to DEPT1@ourdomain.com , email is received to all members in this DEPT1 users group.
Our understanding was that these are local groups and user can send email to these groups who are locally using either lotus notes or lotus web mail. but this happened that lotus automatically distributed email to this group members whereas there is no such email created in domino with name of DEPT1@ourdomain.com
As a temporary remedy we created mail rule in domain to reject email if TO,CC,BCC is DEPT1 (except for dept. heads users). but there are 100+ groups, so what is the recommended method to prevent sending email from outside to local...