==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Centos 7
Test of new install about 2 weeks ago with updates applied today (kernel, sope49, sogo, rsyslog, python-perf).
Mysql

Have an unused domain with a test.user account and sends email out.  RoundCube shows red box stating interal server error though on interface (attached).  Appears from docs that RoundCube logs to: /var/log/maillog.

Does it in fact log there? 

Example: errors
Jun 27 23:50:51 m01 postfix/error[1835]: 49YnmH2prdzDy7: to=<postmaster@domain_name.com>, relay=none, delay=2490588, delays=2490588/0.15/0/0.08, dsn=4.3.0, status=deferred (address resolver failure)

Jun 27 23:50:51 m01 postfix/error[1835]: warning: proxy:mysql:/etc/postfix/mysql/relay_domains.cf: table lookup problem
Jun 27 23:50:51 m01 postfix/error[1835]: warning: 49YnmH2prdzDy7: flush service failure

Jun 27 23:50:51 m01 postfix/cleanup[1829]: warning: proxy:mysql:/etc/postfix/mysql/virtual_alias_maps.cf lookup error for "root@m01.domain.tld"

Jun 28 01:10:02 m01 postfix/trivial-rewrite[1882]: warning: proxy:mysql:/etc/postfix/mysql/transport_maps_maillist.cf lookup error for "*"

What is wrong and/or am I missing?