What is the relationship between MS-Outlook PST file and MS-Outlook MSG File?

Question

Is there any relationship between a MSG file format and a PST file format?

I was under the assumption that a PST file format is an archive that holds many MSG file formats...

For example, if I want to get an email subject from MSG file I would extract it from stream "__substg1.0_0037". However if the same email is stored in a PST I would get the subject from the content table property: 0x0037.

I can see that the 0037 is common in both cases, but if I extract the byte array associated with the email in the PST and save on my hard-drive and then tried to open it using outlook, would outlook recognize it as a true MSG file?

I haven't tried this yet, because I'm having difficult time extracting the byte array from the PST.

Answer 1

No, absolutely not - MSG is an OLE storage file. You can read its streams and storage objects using the standard Windows API. Its format is documented at http://msdn.microsoft.com/en-us/library/cc463912(v=exchg.80).aspx

PST file format is documented at http://msdn.microsoft.com/en-us/library/ff385210(v=office.12).aspx