> On Sun, Oct 11, 2009 at 01:34:58AM +0200, mouss wrote: > >> > How can I configure Postfix to use vpn.mydomain.tld on IP B? >> >> create two smtpd listeners in master.cf, one for each IP, and use -o >> myhostname to set the hostname. >> >> 192.0.2.1:25 .... smtpd >> -o myhostname=vpn.example.com > > This answers the OP's question, but perhaps one should ask why the OP > believes this to be a good idea? There is generally no requirement for > the SMTP server to appear to have a different name for each IP address > it is listening on. > > Unless one is sufficiently motivated to use a separate Postfix instance > for each interface, there is little to gain from different host names > on different IPs. >
It's a try to avoid UCE but get valid mail fast. The idea is to set the first MX-Record of the domain to an invalid hostname, the second one to the first IP of Postfix and the third one to the second IP of Postfix. My hope is spammers will give up on the first invalid MX-record while a correctly configured MTA will try the second MX-record and get's a temporary server error from Postfix-GLD and tries the third MX-record on which Postfix-GLD accepts the mail as it has been greylisted on the second MX-record/first IP, while lazy spammers will give up before. All OpenRelay-test-tools complained about the wrong hostname and TLS doesn't like wrong hostnames either. ;) So, let's try if it works. Currently about 99% UCE doesn't make it to the mailboxes, with nothing else than the three MX-records and Postfix-GLD used for UCE (I must be stupid to post this idea, as any spammer will read this ML ...). Best regards, Rene Bartsch
