The team is developing a scalable PST file migration application, for as much as terabites of old PST Files -- At this time, we need to retrieve email messages from PST file. We are using MAPI to do this. We also want to know which mailbox user this pst file belongs to. The question #1 is how we can get the mailbox owner information for each pst file? The second question is on PST file is sometimes we only get X400 addresses instead of Internet address. How do we get Internet address from an X400 address? or maybe there are MAPI api to get Internet address directly?