Happy new year to all of you ! ;o)

I'm trying to setup a postfix antispam gateway to our mail server.

Something looking like :

Internet --> mx1.mydomain.com[my gateway with postfix] -->
mx2.mydomain.com (only MX1 acts as a DNS MX for all emails sent to
mydomain.com)

It works pretty well, with restrictions I planned, but I have two problems I
cannot solve for some weeks :

1/ relay_recipient_maps seems not to filter emails sent to mx2.mydomain.com
(it was postmap'ed).

mx2 is contacted to verify if user email exists instead of looking up into
/etc/postfix/relay_recipients file.

Did I miss something ??

2/ the most important problem is the mail return message following a non
existing user sending email :

The Postfix program

< ... at mydomain dot com>: host mx1.mydomain.com[xx.xx.xx.xx] said:

550 5.1.1 < ... at mydomain dot com>: Recipient address rejected:

undeliverable address: host mx2.mydomain.com[xx.xx.xx.xx] said:

550 5.1.1 < ... at mydomain dot com>: Recipient address rejected: User

unknown in local recipient table (in reply to RCPT TO command) (in reply
to

RCPT TO command)

For security reasons, is there a way to hide this notification, and say
instead something like "User unknown" ?

Or just notify the first line about mx1 without any mention to mx2 ?

Thank in advance for your replies.

Antony

Here are the configuration files of mx1.mydomain.com

#cat main.cf

invalid_hostname_reject_code = 550

multi_recipient_bounce_reject_code = 550

non_fqdn_reject_code = 550

unknown_sender_reject_code = 550

unknown_virtual_alias_reject_code = 550

unknown_virtual_mailbox_reject_code = 550

unverified_recipient_reject_code = 550

unverified_recipient_reject_reason = Address lookup failed !

show_user_unknown_table_name = no

smtpd_banner = Mailbox Machine

biff = no

disable_vrfy_command = yes

smtpd_helo_required = yes

append_dot_mydomain = no

smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem

smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key

smtpd_use_tls=yes

smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache

smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache

mydestination =

local_recipient_maps =

local_transport = error:local mail delivery is disabled

myorigin = mydomain.com

mynetworks =

127.0.0.0/8

parent_domain_matches_subdomains =

debug_peer_list,

smtpd_access_maps

relay_recipient_maps = hash:/etc/postfix/relay_recipients

relay_domains = mydomain.com

transport_maps = hash:/etc/postfix/transport

show_user_unknown_table_name = no

virtual_alias_maps = hash:/etc/postfix/virtual

smtpd_client_restrictions =

smtpd_helo_restrictions =

smtpd_sender_restrictions =

smtpd_recipient_restrictions =

reject_invalid_hostname,

reject_non_fqdn_helo_hostname,

reject_non_fqdn_hostname,

reject_non_fqdn_sender,

reject_non_fqdn_recipient,

reject_unknown_sender_domain,

reject_unknown_recipient_domain,

reject_unverified_recipient,

reject_invalid_helo_hostname,

reject_unlisted_recipient,

check_recipient_maps,

reject_unlisted_sender,

permit_mynetworks,

permit_sasl_authenticated,

reject_unauth_destination,

reject_rbl_client bl.spamcop.net,

reject_rbl_client list.dsbl.org,

reject_rbl_client zen.spamhaus.org,

reject_rbl_client cbl.abuseat.org,

check_policy_service inet:127.0.0.1:60000,

permit

smtpd_data_restrictions =

reject_unauth_pipelining,

permit

smtpd_end_of_data_restrictions =

# cat virtual

postmaster <a href="mailto: ... at mydomain dot com"> ... at mydomain dot com</a>

abuse <a href="mailto: ... at mydomain dot com"> ... at mydomain dot com</a>

root <a href="mailto: ... at mydomain dot com"> ... at mydomain dot com</a>

cat relay_recipients

<a href="mailto: ... at mydomain dot com"> ... at mydomain dot com</a> xx

# cat transport

mydomain.com smtp:[mx2.mydomain.com]