[Classpathx-javamail] ENVID generation and DSN support

[remi__]

Hi,

I ve just read the implementation of the SMTPTransport class and I need some
explanation about the ENVID generation.
The ENVId is part of the SMTP protocol and provides an "envelope" for the
current SMTP transaction. The transaction is identified by the ENVID, unique
ID. When the message tracking (MTRK property in the Session) is true, an
ENVID is added to the MAIL sommand.

So here are my questions:

Why is the ENVID value different from the Message-ID?
How can we get the ENVID value once it has been generated? Because it is a
good way to track the DSN messages sent from the MTAs to the sender's MUA,
so it would be nice to retreive it after the mail was sent.

Thank you,

Rémi