Well, I've asked this question in Postfix mail list and after discussion as I understand Postfix 2.7 send all necessary client information to Dovecot socket. But I haven't try this solution yet.
2010/2/18 Timo Sirainen <tss@iki.fi>
On Mon, 2010-02-15 at 14:00 +0300, Неворотин Вадим wrote:
allow_nets check failed: Remote IP not known
Problem is clear: smtpd don't send client IP to dovecot authentication socket.
Yep. The only way you can get Postfix to send IP to Dovecot is by patching Postfix sources.
But I need to limit the ability of connection to users only from specific IP. Both for SMTP and IMAP. How can I do that? I use dovecot 1.0.15 and Postfix 2.5.5 on Debian Lenny.
Do you mean all users must connect from only specific IP, or is it a per-user configuration? If all users, maybe you can do this on Postfix side some other way. Or require clients to use submission port or a different IP and use a firewall.