For context: we're currently running 6.0.1 Network Edition on CentOS machines (hosted on Amazon EC2 instances).
To start with, we had successfully enabled outbound DKIM signing by adding the following to ~zimbra/conf/amavisd.conf, then running "zmamavisdctl restart"
Some time later, we configured Zimbra to relay email through our corporate server using:
$enable_dkim_signing = 1;
dkim_key('<dkim-domain>', '<dkim-selector>', '<dkim-private-key-filename>');
@mynetworks = qw(0.0.0.0/8 127.0.0.0/8 10.0.0.0/8);
- "zmprov ms $(hostname) zimbraMtaRelayHost $relayserver:$relayport"
- creation of ~zimbra/conf/relay_config with our values
- "postmap hash:/opt/zimbra/conf/relay_config"
- several postconf's to set smtp_* values
- "postfix reload"
While this works (email is relayed as expected), outbound emails are no longer being DKIM-signed. We don't want to do DKIM signing on the relay server, either, so I have two questions for the Postfix / Zimbra gurus:
- Is this incompatibility likely being caused by an ordering of Postfix operations? (That is, is DKIM signing being done 'after' the relayhost procedure?)
- If so, is there a simple way to reorder these steps, so that mail is signed _before_ being relayed to our corporate server?
I would greatly appreciate any and all feedback. :-)