When preparing to send a message with formatted text, either set the message's PR_RTF_COMPRESSED property to compressed or uncompressed text. Writing compressed text in the PR_RTF_COMPRESSED property is a very CPU intensive operation and can dramatically affect performance.
To improve the performance of sending formatted messages, either:
– Or –
The procedure for setting PR_RTF_COMPRESSED with uncompressed text is the same as for setting it with compressed text, with one exception. When calling WrapCompressedRTFStream, set the STORE_UNCOMPRESSED_RTF flag in the ulFlags parameter. Setting uncompressed text has the disadvantage in that it increases the size of messages.