There are other servers for the same domain (application1, application2, etc.) from which I need to send cron job emails.
I cannot send outgoing emails directly from those servers because ISP hasn't added PTR records for them so email get rejected from GMail, HotMail, et al. So I am trying to relay them via the Zimbra server.
I added the IP's of the other servers in Zimbra's mynetworks using zmprov ms command.
Then added relayhost on appserver1.mydomain.com's /etc/postfix/main.cf. Enabled SMTP authentication. Added credentials to /etc/postfix/sasl_passwd
Sending email from root user gets rejected with a FROM error. I created an account called 'relay' on zimbra. From appserver1, I used: mail -r relay email@example.com, etc...
Still getting the message on appserver1:
May 18 11:20:54 server1 postfix/qmgr: 2CD754027FC93: from=<firstname.lastname@example.org>, size=485, nrcpt=1 (queue active)
May 18 11:20:56 server1 postfix/smtp: 2CD754027FC93: to=<email@example.com>, relay=zimbra.mydomain.com[18.104.22.168]:587, delay=5274, delays=5272/0.04/2.1/0.19, dsn=4.3.0, status=deferred (host zimbra.mydomain.com[22.214.171.124] said: 451 4.3.0 Temporary lookup error (in reply to MAIL FROM command))
The FROM address is the mailbox I created, so what am I doing wrong?