Hi, I have a trivial question, which could become a wish list feature.
There are three MTAs. First is a web server postfix instance that relates all mail to the second MTAS, a relay server, which can send mail directly to the world. This relay server and a third MTA are two postfix multi instances. The relay server is for all kinds of other satellites (other machines with i.e. Cron and log heck messages), for some business customers, who want to send newsletters or mails with a little bit larger attachments. Short: the relay server may become in trouble, if bad recipient addresses are in place, The third instance is the real MTA. All received mail is coming in on this instance, as normal mail from submission is sent to the world. This server also does SPF, DKIM, DMARC on incoming mail. Now the problem that came up this day: A customer has a website the probably has a contact form. Internally it sends mail with sendmail command, setting the envelope address to webmas...@domain.tld. Unfortunately the form does set a From:-header to an AOL address. The email destination is managed by the real MTA. So what happened? Mail arrived on www with sendmail, was delivered to the relay server that contacted the real MTA and this server rejected the mail with DMARC policy. Fully correct behavior. Now my question: When the relay server determines the MX for a recipient address, is there any table that works like this: MX host is foo bar, use transport SMTP:[some.mta]:12345 So I could define a SMTP-in for the relay server, if the real MTA is responsible for the destination. I could disable all kinds of millers and make the relay server a mynetworks only hook. Thanks in advance Christian
