Hi,
I am currently using Postfix to relay email to a remote SMTP server run by the company I work in (we use it for sending Nagios notifications). As this network connection is occasionally not so reliable we would like to use a 3G connection as a backup network connection and doing so would require using the mobile company's SMTP server. After searching online and reading a lot it seemed to me that, assuming that the company's SMTP server is 100.100.100.100 (for one reason or another we use the IP address rather than FQDN) and the 3G operator's SMTP server is smtp.3g.com, what I needed was this in the Postfix configuration: relayhost = 100.100.100.100 smtp_fallback_relay = smtp.3g.com The idea being that when the link to 100.100.100.100 is down (as in that network connection is down) the machine failsover its network connectivity to the 3G one and uses smtp.3g.com. Now, the network failover is working fine (this is on Ubuntu 9.04). No problems there at all. My problem is that Postfix is still trying to relay to 100.100.100.100. I tested this by pulling out the network cable. The ethernet link was down and the machine was using the 3G network. So, have I done anything wrong? I should say that the remote smtp server on the company's network isn't needed, I had Postfix working perfectly sending mail from this office (although it is routed through the office where the smtp server is anyway). I merely set it up with the relayhost as my understanding was that to have an smtp_fallback_relay one needed to have a relayhost in the first place. I am not in the position to change anything on the 100.100.100.100 smtp server but I have complete control over the machien running Postfix. I also don't have control over the main network DNS but I could possibly convince those that do have the power to make minor changes. Of course I can set up some form of DNS server on the Postfix server machine (running Ubuntu 9.04) if required. I only say this as there seem to be a lot of talk about DNS MX records regarding this topic on the net, although I am yet to find anyone that solves my exact problem. So, can anyone help me? Thanks in advance for any help received. Regards, Mark Baxter ________________________________ Mark Baxter OnDemand Administrator Visma Proceedo AB Rålambsvägen 17, vån 12, S-112 59 Stockholm, Sweden Switchboard : +46 8 522 930 30 Direct : +46 8 522 930 60 Mobile : +46 73 978 92 60 Fax : +46 8 58 88 48 29 Internet : http://www.vismaproceedo.com <http://www.vismaproceedo.com/> E-mail : mark.bax...@visma.com Ekonomisystem - Elektronisk fakturahantering - Redovisning - Tid- och projektstyrning - Säljstödssystem - Lön - Inkassotjänster - Inköp - Butiksdatalösningar - E-handels- och webblösningar This communication is intended for the person(s) named above only. It contains information that is confidential and legally privileged. If received in error, please delete this e-mail and notify the sender. ________________________________
