Some properties can and will be different, e.g. PR_SEARCH_KEY. Most likely
neither you nor your users care about these properties, but they will be
make the MSG fiel different.
Secondly, the order in which properties are streamed to the MSG file can be
different, so even if the mesasge is the same, the hash will be different.
You need to use a different algorithm to determine whether two messages are
the same, such as comparing the message body, subject, recipients, etc.

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"peketi" wrote in message
news
I am writing an application that generates a message digest (MD5) for a MSG
file generated by Outlook application. If I generate a MSG file each from
2
PST files, FILEA.PST and COPY_OF_FILEA.PST (* COPY_OF_FILEA.PST is a copy
of
FILEA.PST *), A.MSG and A1.MSG, I get a hashvalue or the message digest
different for these messages though the content of these messages are
same.
Any reasons for this and workarounds ?