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Re: Mail forward only using virtual_alias_maps

From: Jerrale Gayle (jerralegaylesheltoncomputers.com)
Date: Thu Jun 10 2010 - 17:59:33 CDT


On 6/10/2010 1:06 PM, Chad Morland wrote:
>
>
> On Thu, Jun 10, 2010 at 11:53 AM, Noel Jones <njonesmegan.vbhcs.org
> <mailto:njonesmegan.vbhcs.org>> wrote:
>
> On 6/10/2010 10:20 AM, Chad Morland wrote:
>
> I am trying to setup a server that will be only used for mail
> forwarding
> and will not have any local mailboxes on it.
>
> I am trying to have virtual_alias_maps as the sole lookup and
> any other
> mail is rejected during the SMTP session after the RCPT TO
> command if
> the address is not found in virtual_alias_maps.
>
> I have the following in my configuration which works:
>
> smtpd_reject_unlisted_recipient = yes
> virtual_alias_maps =
> proxy:mysql:/etc/postfix/mysql_virtual_alias_maps.cf
> <http://mysql_virtual_alias_maps.cf>
> <http://mysql_virtual_alias_maps.cf>
>
> virtual_alias_domains =
> proxy:mysql:/etc/postfix/mysql_virtual_domains_maps.cf
> <http://mysql_virtual_domains_maps.cf>
> <http://mysql_virtual_domains_maps.cf>
>
>
> I'd like to do away with virtual_alias_domains but when I
> disable this I
> get "relay denied".
>
> Is there a way to configure postfix so that it is the final
> destination
> only for addresses defined in virtual_alias_maps and not the
> entire
> domain as implied by virtual_alias_domains?
>
>
> You can use the "old" method of defining virtual_alias_domains by
> defining them directly in virtual_alias_maps.
> key value
> example.com <http://example.com> anything
>
>
> If your domain list doesn't change often, just list the domains in
> main.cf <http://main.cf>. If there are more than a handful of
> domains, use a static hash: table.
> http://www.postfix.org/postconf.5.html#virtual_alias_domains
>
>
> Thanks for the idea but it doesn't address my issue. I don't want to
> accept mail for the entire domain, just for specific addresses that
> are defined.
>
> Also, this system has thousands of domains and aliases which are
> updated frequently so I'm going to be sticking with the MySQL backend.
>
> My application is a DNS management system and my current DB schema has
> a table that lists all domains in the system (virtual_alias_domains)
> regardless if they have mail forwarding setup and another table that
> lists the alias info (virtual_alias_maps). I only want postfix to
> accept mail for addresses defined in virtual_alias_maps.
>
> My current setup (using virtual_alias_domains) will accept mail for
> the entire domain and generate a bounce message if the user does not
> exist. I want to stop that at the SMTP session level.
>
> Example:
> virtual_alias_maps = fooabc.com <mailto:fooabc.com> -> fooxyz.com
> <mailto:fooxyz.com>
>
> Accept mail for fooabc.com <mailto:fooabc.com> but reject mail at
> the SMTP level for barabc.com <mailto:barabc.com> (550 relay denied).
>
>
Well, the server doesn't have to reject anything except for those
connecting directly to it without using the MX. The mx record does not
allow partial domain matching; so, your regular postfix server would
have to accept all mail for the domain and then forward the specific
mail to the other server. I would actually suggest using ONE mail
server, or multiples with the same config as backups, for all your
mail, including your rewrites, to save headache because having mail
forwarded from one postfix server to another, and then forwarded again,
will cause the final destination address to not be what you expect. You
would need to have the main postfix server forward to a subdomain of the
domain, such as forward.domain.com handled by the second server, and
then the final recipient would think their e-mail address is
fooforward.domain.com. *The only way to avoid this is by using
transports on the main postfix server to point to the second server as
the transport.* So, you need to look into transports!