The safest, most reliable way to transfer from XP to Win7 is to install Pegasus Mail on the Win7 machine, configure it as needed using the XP install for reference, then restore messages, folders & addressbooks from the mailbox directories on the XP machine to the mailbox directories on the Win7 machine.
Worthy of note:
- Pegasus Mail can not be installed anywhere inside of \Program Files (default is C:\PMAIL)
- Care must be taken not overwrite any configuration files when transferring data from the XP machine.
There is a guide to Pegasus Mail filenames and file-extensions that is useful in determining which files you may want to transfer over. It is located here:
http://www.vandenbogaerde.net/pegasusmail/pf_pmfiles.html
There is no guide for this process because there are too many variables. A benefit of Pegasus Mail is its flexibility but in this case that flexibility is also a curse. We are here to answer any specific questions you may have about whether a file is safe to copy from a previous installation.
To answer your specific question about the \Mail directory, that directory contains the Pegasus Mail user list and the mailbox directories. It can not be copied intact because most of the Pegasus Mail configuration files reside inside of the mailbox directories and are installation specific. Many folks have had success with a wholesale copy but there are caveats to making this work and no guaranties that it won't introduce problems that are difficult to troubleshoot.
If you would like you can send me a private message containing your
email address and I will send you some additional information that is
too detailed to post here.