On Tue, Apr 07, 2015 at 10:30:36AM -0400, chris wrote: > Hello, > > I have a few linux webservers and which each send out SMTP directly . > Currently, the webservers all relay the message directly to > receipient and if it cant then it sends back a NDR to the sender > advising the sender the message could not be delivered. > > I want to scale this out a bit and add 2 "backup" SMTP server but > what I want to do is have the webservers try to deliver the message > and also have both SMTP A and SMTP B as backup relays and I want it > so that if the webserver cannot deliver the message directly then > have it try SMTP A, this server would keep the connection to > webserver open and attempt to relay right away and if it fails REJECT > the message so the webserver will try the next server SMTP B etc etc. > > I am just wondering if anyone knows how to do this or something like > it. As far as MTA I am familiar with exim,postfix,sendmail and not > tied down to a specific one so whichever gives this functionality is > fine. > > Basically the problem I am trying to solve is to have a little bit of > SMTP HA sort of so that if lets say the webserver cant reach the > receipients mail server due to some routing problem or lets say if > the receipient mail server has some kind of firewall that was > blocking certain ranges of IP's, then we just want the message to > retry on some other SMTP relays which we can spread out on different > networks as backups so we can hopefully just get the message > delivered an alternate way to buy us time to look into why it couldnt > be delivered the normal way. > > I am not really like looking for a commercial solution but rather to > build the setup out of existing open source software. We are all > command line ninjas so we dont need a point and click gui or any > appliances :) > > If anyone has a setup like this I'd be curious to pick your brain and > see what worked and didnt work for you.
I'd say ditch the direct delivery completely, set up your SMTP servers and give them an alias like 'smtp.yourdomain.com' and then point your web server at that alias for all mail. If one of the SMTP servers goes down, the local MSA on your web servers should be smart enough to try the other instance. You'll also have fewer outgoing IP's to worry about managing from a reputation standpoint... Ray _______________________________________________ mailop mailing list [email protected] http://chilli.nosignal.org/mailman/listinfo/mailop
