[Dovecot] when/where to set MAIL env variable?

[Mike Brown]

Andrew Basterfield wrote (in a msg I don't think made it to the list):
> In dovecot.conf
> 
> default_mail_env = maildir:~/Maildir

Ah, silly me...

default_mail_env = mbox:~/Mailbox

works wonderfully, and is easier than trying to figure out
where the MAIL environment variable actually comes into play.

Thanks...