Inbound Only postfix gateway on home network/server lab
- I am setting up an inbound postfix instance to run on a dmz host.
Its purpose is to accept mail only for specific relay_recipients and to
transport them to an internal postfix server.
I have demonstrated proof of concept with this * but there is a tweak I
cannot easily figure out from the documentation after having tried a few
obvious options and reset them. Something basic is missing from my
understanding, correcting which would be appreciated.
Firstly I need to be sure that nothing entering this server will go out
to the internet.
All traffic needs to go to the internal smtp box which maildrops stuff
into local unix accounts.
There is a third box running outbound postfix which is meant to receive
outbound mail from clients and have access (in the first place) to my
If this seems overengineered, sorry. But I am attempting to learn the
details and having things on separate boxes helps.
Anyway, the issue I am tussling with is that mails destined from
internal hosts don't resolve locally and instead escape out to my ISP's
smarthost where they are picked up with an invalid domain and bounced. I
would like to stop this behaviour.
Which fragments of my various configuration files would be useful to
help diagnose this?
I observe that mails are escaping directly from this machine and not
going to the internal maildrop server nor to the outbound smtp box. In
fact, the inbound postfix service is attempting to resolve the internal
address as an Internet domain "Diagnostic-Code: X-Postfix; Host or
domain name not found. Name service error for name=xxxxx.yyyyy
type=AAAA: Host not found".
where xxxxx.yyyyy is the internal host I was trying to send to.
Anyway this is probably dead simple to someone :-(
Thanks in advance
* with a previous ISP but have now transferred to another and would like
to revive control of inbound mail.
- Wietse Venema wrote:
> David Denny:# postconf -c /etc/postfix_daviddenny.co.uk/ -n
>> Which fragments of my various configuration files would be useful to
>> help diagnose this?
alternate_config_directories = /etc/postfix /etc/postfix_chavin.net
command_directory = /usr/local/sbin
config_directory = /etc/postfix_daviddenny.co.uk/
daemon_directory = /usr/local/libexec/postfix
debug_peer_level = 2
html_directory = /usr/local/share/doc/postfix/html
inet_interfaces = 10.0.3.227
inet_protocols = all
mail_owner = _postfix
mailq_path = /usr/local/sbin/mailq
manpage_directory = /usr/local/man
mynetworks = 10.0.3.227/32,10.0.1.8/32
newaliases_path = /usr/local/sbin/newaliases
queue_directory = /var/spool/postfix_daviddenny.co.uk
readme_directory = /usr/local/share/doc/postfix/readme
relay_domains = daviddenny.co.uk
relay_recipient_maps = hash:/etc/postfix_daviddenny.co.uk/relay_recipients
sample_directory = /etc/postfix
sendmail_path = /usr/local/sbin/sendmail
setgid_group = _postdrop
smtpd_banner = $myhostname ESMTP $mail_name daviddenny.co.uk AT grasberg
transport_maps = hash:/etc/postfix_daviddenny.co.uk/transport
unknown_local_recipient_reject_code = 550
virtual_alias_maps = hash:/etc/postfix_daviddenny.co.uk/virtual