IMessage::SaveChanges()
 

Hello all,
I've added a HTTP account to my Outlook (Hotmail account). A new PST added,
and now the SaveChanges() failed when I call it for messages in this PST
(error 0x8004DFF7). Is there any fix for this? All what I want to do is
adding a named property.
If this a normal behavior;
1. What are the kinds of accounts that cause the same issue? As an example,
does the IMAP accounts cause the same?
2. How can I programatically distinguesh between PSTs that I can update and
that I can't?

Thanks