Greetings, I should know the answer to this but I don't. Very embarrassing.
The problem is my inside the firewall, backup mail server. mxhost2 (ns6) in the dig output below. -------------------------------------------------------------------------------- # dig -t MX arlut.utexas.edu ; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.2 <<>> -t MX arlut.utexas.edu ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8190 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 3, ADDITIONAL: 5 ;; QUESTION SECTION: ;arlut.utexas.edu. IN MX ;; ANSWER SECTION: arlut.utexas.edu. 21600 IN MX 15 mxhost2.arlut.utexas.edu. arlut.utexas.edu. 21600 IN MX 10 mxhost1.arlut.utexas.edu. ;; AUTHORITY SECTION: arlut.utexas.edu. 21600 IN NS dns3.arlut.utexas.edu. arlut.utexas.edu. 21600 IN NS dns1.arlut.utexas.edu. arlut.utexas.edu. 21600 IN NS dns2.arlut.utexas.edu. ;; ADDITIONAL SECTION: mxhost1.arlut.utexas.edu. 21600 IN A 10.4.1.6 mxhost2.arlut.utexas.edu. 21600 IN A 10.4.1.23 dns1.arlut.utexas.edu. 21600 IN A 10.4.1.2 dns2.arlut.utexas.edu. 21600 IN A 10.4.1.3 dns3.arlut.utexas.edu. 21600 IN A 10.4.1.24 ;; Query time: 0 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Wed Oct 13 11:02:46 2010 ;; MSG SIZE rcvd: 219 -------------------------------------------------------------------------------- Here's the main.cf, trimmed to save bandwidth. myhostname = ns6.arlut.utexas.edu mydomain = arlut.utexas.edu myorigin = $mydomain inet_interfaces = all mydestination = local_recipient_maps = relay_domains = relayhost = ns4.arlut.utexas.edu relay_recipient_maps = hash:/VOLUMES/postfix/etc/pfknown_users smtp_generic_maps = hash:/VOLUMES/postfix/etc/pfgenerics alias_maps = hash:/VOLUMES/postfix/etc/pfmalias, dbm:/VOLUMES/postfix/etc/aliases transport_maps = hash:/VOLUMES/postfix/etc/pftransport local_transport = error:local mail delivery is disabled -------------------------------------------------------------------------------- Here's the question: This backup machine, IMHO, ought to be able to deliver mail to internal machines without going through the primary, internal mail server (mxhost1). It isn't. Mail leaving my site from ns6 should go straight to ns4, and not touch mxhost1. It isn't. It seems ns6/mxhost2 can't do anything without mxhost1. Why? My answer is that (from the dig output) mxhost1 is lower cost than mxhost2 everything goes to mxhost2. That explanation isn't entirely satisfactory even to me, because even outbound mail from ns6 goes through mxhost1 even though the relayhost is set to ns4. So, my first question is, to be explicit: why is mxhost1 getting involved? Why isn't mxhost2/ns6 taking care of this itself? Second question: what needs to change so that mxhost2/ns6 does start doing things without bothering mxhost1? (I sent test emails from mxhost2/ns6 to inside and outside addresses and the headers show they all go through mxhost1.) j. -- Jay Scott 512-835-3553 g...@arlut.utexas.edu Head of Sun Support, Sr. System Administrator Applied Research Labs, Computer Science Div. S224 University of Texas at Austin
