So my quest for help has met no answers so I ask all of you this question:
If you receive notes mails on your phone(windows mobile 5)with a middle initial in the name, example: "James T. Kirk"
Thus when you reply, the lookup on Domino directory is invalid and you get a dead message error email.
Perhaps it is a configuration issue we have made but as it started to happen out of the blue I am not sure.
The implication is Domino is forwarding the email incorrectly. It arrives fine in my notes client inbox, just not on my phone.
Anyone with similar experience or pointer to resolve it let me know.
In the meantime I took out the middle initials of users names and that resolved the immediate problem.