Hi Trent,

Thanks for your exhaustive explanation now it is clear. What was unclear to me was the fact that the IMAP proxy server has to take care of the authentication in this case of using a master user and therefore it needs access to the passwords (in my case stored in the mailbox table in PostgreSQL). I still have two open questions:

1. Do I really need the userdb on my IMAP proxy config as you mention in your mail? In my understanding the passdb should be enough (which in my case will use a SQL query joining the result of my proxy and mailbox tables).

2. Is this correct that the IMAP backend (the mailbox server) in this case scenario has to use PLAIN authentication and can NOT use CRAM-MD5?

Regards,ML