How To Configure Outgoing SMTP Authentication on Zimbra 8.7

How To Configure Outgoing SMTP Authentication on Zimbra 8.7

When we need to route all outgoing mail through your ISP’s MTA, and that MTA requires that you authenticate, certain settings in postfix are required.

Required outgoing SMTP mailrelay

SMTP Relay : relayserver.server.lan
Username : relayacc@server.lan
Password : Relay@Sev
Port : 25 / 587 / 465

Let’s create a relay access file for zimbra authentication to outgoing SMTP, and create a file relay_access as follows:

# vi /opt/zimbra/conf/relay_access

relayserver.server.lan relayacc@server.lan:Relay@Sev # add this line

save and exit

Now postmap relay_access

# postmap /opt/zimbra/conf/relay_access

To enable outgoing mail for zimbra

# zmprov ms `email.server.lan` zimbraMtaSmtpSaslPasswordMaps lmdb:/opt/zimbra/conf/relay_access
# zmprov ms `email.server.lan` zimbraMtaSmtpSaslAuthEnable yes
# zmprov ms `email.server.lan` zimbraMtaSmtpCnameOverridesServername no
# zmprov ms `email.server.lan` zimbraMtaSmtpTlsSecurityLevel may
# zmprov ms `email.server.lan` zimbraMtaSmtpSaslSecurityOptions noanonymous

# zmprov ms `email.server.lan` zimbraMtaRelayHost relayserver.server.lan:587 -> The port may change it

No need reload postfix, it will automatically update within 2 minutes, change the necessary action for mx to DNS.

Note : If mails are not being delivered while checked mail.log. We need to confirm our SMTP ports like 465 or 587 because of some ISP’s not enable TLS properly. So on time change the port will as above formet mention.

That’s it 🙂