==== Required information ====
- iRedMail version: latest stable
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: Debian Wheezy
- Related log if you're reporting an issue:
====

It's really annoying and confusing that it's not possible to search for an receiver by alias domain.
You always have to search by Master Domain, which might make sense technically, but not from a customers standpoints view.

Example:
Master Domain: domainA.com
Alias Domain: aliasB.com
Mail is sent to: user@aliasB.com

Searching for this email is only possible by searching for user@domainA.com
What we need is searching for user@aliasB.com to show the same results as user@domainA.com.

This shouldn't be too hard to fix, i guess.
A regular customer does not understand the need to search for the master domain to find the result for the alias domain.
It would burst usability for the customer and make the search naturally understandable, limiting the amount of explanation to the customer.