No, the MAPI named property isn't carried over. But neither would the
Internet headers be carried over, so the design is flawed if it counts on
either property being there in a reply.

In an addin you can handle the Reply() event on a selected item or items,
and by handling the Reply() event on an opened item you are notified about
by the NewInspector() event.

Then you can add whatever MAPI properties you want to those newly opened
Reply items.

ConversationIndex and ConversationTopic are used to link an original item
with a reply or replies. Each item in the conversation has the same
ConversationTopic. ConversationIndex has a new date/time structure appended
to it for each new item in the conversation. So you can look for items with
that ConversationTopic to find the conversation, and evaluate the
ConversationIndex property to see which has a value there that's one entry
shorter than the current item.

--
Ken Slovak
[MVP - Outlook]
http://www.slovaktech.com
Author: Professional Programming Outlook 2007.
Reminder Manager, Extended Reminders, Attachment Options.
http://www.slovaktech.com/products.htm


"Mark B" wrote in message
...
So when a user hits the reply button is the MAPI property of the original
email carried over into the new email so that when the user finally hits
the Send button on the new email we can interpret which email they are
replying to?

We only need to ascertain all this within the Outlook client itself on the
desktop -- we don't need it to be included after it leaves via the Send
event.

In summary -- an email comes in, we want to add a property with a specific
identifier and that gets stored within the email. Then later when the user
replies to that stored email, the new email has a new property to store
the original email's property value. Then when they eventually click Send
we perform our action if certain criteria based on the property are met.