Am 28.04.2005 um 12:46 schrieb Dan Shoop:
At 9:37 AM -0300 4/28/05, Dr. Rolf Jansen wrote:
Hi,
I set up a Mac OS X Server 10.3.9 in Brazil and its mail service is
running now perfectly, except that for any reason a major online
service based in US blocks our static IP address. Their postmaster
web site is merely a fake site, there postmaster help desk phone
number is dead, the postmaster e-mail address produces only
automated response messages. So I gave up, since there seems to be
no way to let them unblock our IP.
My idea is now, to relay mail to their members by our SMTP server in
Germany, which is not blocked by them. However, I do not want to
relay all mail from Brazil by the German server, since this involves
too much unnecessary long distance traffic.
I know, how to change the Postfix configuration files to relay all
mail by another SMTP host. But, how do I relay only for certain
destinations by another SMTP host? Is this feasible at all?
This is an area where exim excels and I'd suggest using it instead of
postfix. You can easily create separate mail routers in exim to
examine the recipients and based on their domain route the mail
through a smarthost or relay appropriate for them. Thing of this as
the smtp equivalent to routing in TCP/IP.
Many thanks to Marshall Eubanks and Dan Shoop for their kind replies.
I found a solution also for Postfix. Here comes, what I did:
1. add the following 2 lines at the top of the file
/etc/postfix/transport and then 'postmap transport'.
aol.com smtp:the.german.server.de
* :
2. add the following line to main.cf and then 'postfix reload'
transport_maps = hash:/etc/postfix/transport
3. add the static IP of the Brasilian Server to the "mynetworks"
variable of main.cf of the German server
That resolved my issue with aol.
My concern is now, whether some spammer can now spoof the IP of the
Brasilian server and successfully let the German server relay their
spam. If this is a real danger, then I need to take other measures.
Best regards
Rolf Jansen
