Sorry that I only stumbled on this issue today. I have also cross-posted the following reply at my blog
This is for Sametime 8.0 on Domino 8.0 pointing to AD for authentication with an Exchange server.
When trying to get the meeting notifications to work, I initially recieved this error:
Dead Failure Reason:User Sametime Development/Lotus Notes Companion Products (Sametime Development/Lotus Notes Companion Products@Domain) not listed in Domino Directory
After enabling smtpclientdebug=1, I was seeing that the error was actually similar to this thread.
Specifically, the error is: SMTPClient: Error parsing from address
The key part of this error is that it's an error parsing from address. To make a long story short, I ended up having to open STConf.nsf in Domino Designer, then opening the the "sendnotification email" script library. In the sub used for notifications, I had to modify what was being used for the sender's address.
One note is that you should create a Sametime Admin account on the Domino server as well as on the Exchange server. In Exchange, you could create a Sametime Admin group to receive the replies if you would like. Here's what I changed to not only solve the issue above, but to also make the Outlook Client display a name in the Inbox folder.
Look for the following If loop and replace it with the following code down to the line that is: Set header = body.CreateHeader("Sender")
If (sendEmailFrom = "") Then
'sendEmailFrom = meetingDoc.STCreator(0)
sendEmailFrom = "firstname.lastname@example.org"
' The following three are the best way to ensure that the client renders the
' sender's address correctly. When modifying the principal field, Domino must
' be able to resolve the address in the local directory (from my understanding and
' prior troubleshooting).
doc.From = "Sametime Admin"
doc.Principal = "Sametime Admin"
doc.replyto = "Sametime Admin"
' You can just use the internet address for the following sender fields.
doc.SendFrom = sendEmailFrom
doc.DisplaySent = sendEmailFrom
doc.AltFrom = sendEmailFrom
doc.INetFrom = sendEmailFrom
doc.tmpDisplayFrom_Preview = sendEmailFrom
doc.tmpDisplayFrom_NoLogo = sendEmailFrom
doc.tmpDisplaySentBy = sendEmailFrom