I'm setting up a Postfix and Dovecot combination. What I want to do is have a user database that (1) is not running from some engine (so not LDAP or SQL or such) ... and (2) is completely disassociated from system users (e.g. most email users are not in /etc/passwd and most /etc/passwd users are not email users). Ideal would be a one-file solution, which can be managed by text editing or simple command line tools. But what I want is ONE file that both Postfix (for valid recipients) and Dovecot (for user login authentication) can use together. An alternative is some way to get Postfix to go through Dovecot to query for users (at the time of mail arriving on SMTP so it doesn't queue anything that would later be rejected). This is a smallish setup on one server, with probably a max of 50 to 100 users and 50 or so role account mailboxes over the next year or two. Any recommendations?