A golden tidbit I just learned - This new ND6 INI parameter blocks mail to Domino Directory groups. A thing SPAM’ers love to do to my organization:
RouterDisableMailToGroups=1
Without going into the domino SMTP mail group exploit details… mail rules, this ini parameter, or a SPAM blocking hardware solution are the only non-exploitable ways to stop Internet mail to Domino groups that need to be internally mail-able.
Enjoy!
Subject: Block Internet Mail to DomDir Groups
not very helpful though if your smtp router is your domino router to other parts of your business (ie in a global company)
we use underscores in group names that are not to be emailed from the internet, as it gets translated into a space and no longer matches the group name so gets rejected, and for those groups requring internet mailing we add an appropriate internet mail address to the group document.