==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.3
- Linux/BSD distribution name and version: Debian 8.2
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? no
- Related log if you're reporting an issue:
====

Hi!
Looked thoroughly in database structure and configs and found potential issue in pro version.
postfix virtual_mailbox_domains contains query:
SELECT domain FROM domain WHERE domain='%s' AND backupmx=0 AND active=1 UNION SELECT alias_domain.alias_domain FROM alias_domain,domain WHERE alias_domain.alias_domain='%s' AND alias_domain.active=1 AND alias_domain.target_domain=domain.domain AND domain.active=1 AND domain.backupmx=0

The problem is: if we select against aliased domain and if either of alias_domain and target_domain is set to active=0 in domain table, result is returned, but it needs to be empty.