A discussion on the lnotes-l email thread led me to check on a clients environment to validate Mike's sanity.
It seems that in the course of upgrading to 8.5.2(in my case 8.5.2 fp1 on client side, 852 HF16 on server) of his domain something broke in the outbound SMTP.
Some background first. In clients with Exchange and Domino it is quite common to have one or the other handle inbound/outbound email. Usually we use Domino for in/out SMTP and any email that needs to go to the other parts of the company on Exchange get addressed as firstname.lastname@example.org instead of email@example.com. So in all Exchange users listed in Domino they have a forwarding address firstname.lastname@example.org.
The way Domino used to send external emails would be if I cc'd or included an Exchange user, the outside party saw email@example.com, not firstname.lastname@example.org.
However right now Domino is sending out as email@example.com since the upgrade(and possibly since going to 852).
While I thought the issue was related to Mike's usage of the Dircat, I mean Mobile Directory for you new admins, that is just a red herring.
iNotes sends an email out properly still when I tested it. So whatever is broken, is only 1/2 broken and evidently has to do with the Notes client side OR the Notes Client 852fp1 hitting 852hf16 has an issue.
So anyone out there who has seen this or wants to provide some insight let us know. Guess it's the Iris lab for me on this one at LS11 if nothing comes up first.
One thing I have never really dug into is all the RFC's and how they got implemented, I am just not THAT geeky although someone in Product Management usually knows these things. Used to be many years ago my friend Mike Harer owned SMTP but these days who knows.