Multiple MTAs?

[NaughtyusMaximus]

I'm wondering if there is any way to allow for two relay MTA entries in Zimbra.

I have two ISPs, I default to using ISP1 for serving email, with my relay MTA set to smtp.ISP1.com. What I would like for is to have a second entry where I can enter smtp.ISP2.com as a relay MTA, for the case when ISP1 is offline. Is there any way I can do this?

[phoenix]

You could vote on this RFE: Bug 32740 – Per domain Relay MTA for external delivery

[uxbod]

You can try

su - zimbra
zmprov gcf zimbraMtaRelayHost

that will list the current relay; and then to add the second relay you would use

zmprov mcf +zimbraMtaRelayHost isp2.domain.com:25

I believe this works as a fallback and not round-robin.

[NaughtyusMaximus]

Hm, unfortunately it doesn't look like that works for me. I'm able to add the 2nd MTA, but after doing so, I get this message in my logs after I disable access through ISP1 (and try to force through ISP2 for testing of failover):

Mar 6 08:55:33 SL-017 zimbramon[30437]: 30437:info: zmmtaconfig: Failed to reload mta rc=256

Sending email begins to time out.

[uxbod]

How are you disabling access through ISP1 ? FW ?

[NaughtyusMaximus]

Yeah, through the firewall. I have it set up in a failover fashion so normally zimbra tries to use ISP1 to send through, and if it is offline, it'll failover to ISP2.

This is what causes the problem, since if I have my MTA relay set to smtp.ISP1.com, and ISP1 is offline, they don't allow relaying when I'm entering through ISP2's connection.

[uxbod]

Hmmm, you could script it in perl ? Have a daemon process that checks whether the remote MTA is responding or not and if it does not switch your relay using zmprov. I presume the routing is handled via your FW/router to bring up the alternate connection ?

[NaughtyusMaximus]

Yeah, if that is the only option, thats what I'll go for. The router is set to do failover automatically