I like to catch the OnSend-Event AFTER the Groupwise-event, because then the message is stored in the database and has a valid MessageID. But how do I recognize which message was just send by the user?
Unfortunately there is no deterministic way of obtaining the message ID of the message that was just sent. This is a strange and frustrating omission from the GroupWise Object API.
However, you can devise a solution to try to find the just-sent message. We cannot guarantee a correct result, but perhaps you can develop a solution in which you have great confidence the result is correct.
I suggest you continue to handle the OnSend (After) event, and obtain some message properties that can be used to identify the message. For example, Subject, creation date, class name. Then look in the Sent Items folder (use the method .FindMessages) using these identifications.
