Does anyone know what these headers are used for?
This one is for Pegasus Email - which can do threading on an
all-Pegasus system. The author of Pegasus found out that some SPAM
companies were providing Pegasus as the emailer for their product,
and he was getting heat for producing SPAMWARE. He changed the
freeware contract forbidding it's use to produce SPAM or UCE. Some
of the spammers, in response, started adding the PMail headerlines to
make it look like they were using Pegasus just to get even.
The Internet - billions of electrons with nothing better to do