when I am sending mail to any address outside of my organisation with an address inside my organisation in the CC field, the person that receives the email has the joe@myorganisation.com format in the from field, but has the Mark/MyOrganisation format in the CC field. When that external person tries to respond to all, they get a non-delivery message saying that Mark/MyOrganisation does not exist, which makes sense.
Is there a setting on my Domino server I need to in order to have intended recipient outside of my organisation see mark@myorganisation.com instead of Mark/MyOrganisation in the CC field.
It appears that making sure the entries in the PAB and directory assistance databases use the Internet address format, rather than the Notes name, prevents the problem.