postfix ignoring -o myhostname/mydestination for smtpd instance in master.cf?

[Wolfram Schlich]

Hi,

let's assume the following setup:

main.cf:

        myhostname = main.example.com
        mydestination = $myhostname

master.cf

        ## 1st smtpd instance on 1.1.1.1
        1.1.1.1:smtp inet n - n - - smtpd

        ## 2nd smtpd instance on 2.2.2.2
        2.2.2.2:smtp inet n - n - - smtpd
                -o myhostname=master.example.com

Nothing special is configured for virtual users,
just local unix users.

With this setup, I can send mail for unix-u...@main.example.com 
to the smtpd on 1.1.1.1 without problems.
I expect the smtpd on 2.2.2.2 to accept mails for
unix-u...@master.example.com, but it doesn't
(relay access denied).

I also tried adding this to the smtpd on 2.2.2.2:

                -o mydestination=master.example.com
        -o relay_domains=
        -o relay_recipient_maps=
        -o virtual_maps=
        -o virtual_alias_domains=
        -o virtual_alias_maps=
        -o show_user_unknown_table_name=yes
        -o local_recipient_maps=proxy:unix:passwd.byname
        -o smtpd_client_restrictions=permit
        -o smtpd_helo_restrictions=permit
        -o smtpd_sender_restrictions=permit
        -o smtpd_recipient_restrictions=reject_unauth_destination

No luck (relay access denied).

Interestingly, when I try to send mail for unix-u...@main.example.com
to the smtpd on 2.2.2.2, it gets rejected with the message
"Recipient address rejected: User unknown in local recipient table",
so it *somehow* seems to honor the mydestination parameter...

When I set -o myhostname=main.example.com for the smtpd on 2.2.2.2,
it accepts mail addressed to unix-u...@main.example.com.

I fail to find out why it doesn't accept mail for
unix-u...@master.example.com :(

Ideas, anyone?

Thanks,
Wolfram