As messages are transferred between messaging systems, the MAPI spooler makes sure that the rich text formatting remains synchronized with the message text. The MAPI spooler calls the RTFSync function from within a wrapped version of the message that it passes to the transport provider. The transport provider saves the changes made to the message by calling the IMAPIProp::SaveChanges method and then routes it to the new recipient.
When the recipient's RTF-aware client application opens the message to display the text, it must synchronize the text with the formatting and open either PR_RTF_COMPRESSED or PR_BODY, depending on which property is available.
RTFSync returns a Boolean value that indicates whether or not the message has been updated. If this value returns TRUE, call SaveChanges at some point to make the update permanent. The call does not have to be made immediately after RTFSync returns.
Note Because so many components handle the formatted text before you receive it, there is the possibility of corruption. This corruption could come from the message store provider, a third party application, a gateway, or a transmission error.