Clients set either the PR_BODY property, the PR_RTF_COMPRESSED property, or both properties for an outgoing message. Clients that support only plain text set only the PR_BODY property. Rich Text Format (RTF)-aware clients might set both properties or only PR_RTF_COMPRESSED, depending on the message store provider being used.
It is important for a client to check its message store's PR_STORE_SUPPORT_MASK property to determine whether the store supports RTF. If the message store is not RTF-aware, an RTF-aware client sets both the PR_BODY and PR_RTF_COMPRESSED properties for each outgoing message.
If the message store is RTF-aware, only the PR_RTF_COMPRESSED property needs to be set.
At this point, if the message store provider supports RTF, you have done all that is required. You can depend on the message store provider to handle the synchronization process and the creation of the PR_BODY property, if necessary. However, if the message store provider does not support RTF, you must call the RTFSync function to synchronize the text with the formatting, setting the RTF_SYNC_RTF_CHANGED flag.