Pigeonhole vacation and envelope extension recipient addresses

[Stephan Bosch]

Op 23-10-2017 om 14:51 schreef David Zambonini:
> I have a situation where my LMTP RCPT TO: goes to a mailbox user account that
> does not reflect either the final (through aliasing) or envelope email address.
>
> SMTP RCPT TO:    (envelope-local-part at envelope-domain)
> Final Recipient: (final-local-part at final-domain)
> LMTP RCPT TO:    (mailbox-local-part at mailbox-domain)

I don't understand the difference between the last two. The first one is 
what I call the original recipient, the last one is what I call the 
final recipient.

How is this supposed to work?

Regards,

Stephan.