> From: owner-postfix-us...@postfix.org [mailto:owner-postfix-
> us...@postfix.org] On Behalf Of Viktor Dukhovni
>
> On Mon, Aug 10, 2015 at 08:50:22PM +0000, Rosenbaum, Larry M. wrote:
>
> > > main.cf:
> > > indexed = ${default_database_type}:${config_directory}/
> > > virtual_alias_maps = ${indexed}virtual
> > > transport_maps = ${indexed}transport
> > >
> > > virtual:
> > > u...@mail.example.com u...@example.com
> > >
> > > transport:
> > > example.com relay:[exch.example.com]
> > >
> > > You can use LDAP to do the rewriting:
> > >
> > > http://www.postfix.org/ldap_table.5.html
> > >
> > > main.cf:
> > > ldap = proxy:ldap:${config_directory}/
> > > virtual_alias_maps = ${ldap}virtual.cf
> > >
> > > virtual.cf (owner root, mode 0700):
> > > server_host = ldap.example.com
> > > search_base = dc=example,dc=com
> > > bind_dn = ... DN of some account object ...
> > > bind_pw = ... corresponding password ...
> > > query_filter = proxyAddresses = smtp:%s
> > > result_attribute = mail
> > >
> > > Test all mappings with "postmap -q".
> >
> > Thanks. One more thing - there will also be other mail with a
> @example.com
> > address that does NOT go to exch.example.com - some will go to e.g.
> > list.example.com, dept.example.com, etc. So it looks like the rewriting
> > and the transport/relay stuff needs to happen at the same time. Is that
> > possible?
>
> Yes, but that is more complicated. You can use per-user transport
> mappings, either indexed file or LDAP equivalent:
>
> transport:
> u...@example.com relay:[exch.example.com]
>
> Or rewrite to destination-specific sub-domains:
>
> virtual:
> u...@mail.example.com u...@exch.example.com
>
> transport:
> exch.example.com relay:[exch.example.com]
>
> Then, as a best-practice, add additional transport addresses to
> each exchange user account:
>
> mail: u...@example.com
> proxyAddresses: SMTP:u...@example.com
> proxyAddresses: smtp:u...@exch.example.com
We're trying to see if we can get rid of that second proxyAddress
> but if that's just too difficult due to extreme bureaucratitis,
> you can undo the rewrite during transmission via smtp_generic_maps
>
> master.cf:
> relay unix ... smtp
> -o smtp_generic_maps=$relay_generic_maps
>
> main.cf:
> indexed = ${default_database_type}:${config_directory}/
> relay_generic_maps = ${indexed}relay-generic
>
> relay-generic:
> @exch.example.com @example.com
>
I think the smtp_generic_maps solution is going to work for us. Thanks.
