[Dovecot] extra fields with "passwd" userdb

[Patrick McLean]

Hi,

I am planning a migration of ~600 accounts to mdbox (from maildir) and
was hoping to do some initial testing of certain account. I am hoping to
use extra fields to migrate certain accounts in advance for testing, and
I can't find info on setting up extra fields with the "passwd" backend.
Is this possible, or will I have to use another approach?