==== Required information ====
- iRedMail version (check /etc/iredmail-release):
- 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?
- Related log if you're reporting an issue:
======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.2
- Linux/BSD distribution name and version: CentOS 6.7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx):Apache
- Manage mail accounts with iRedAdmin-Pro? Yes
- Related log if you're reporting an issue:
====
Hi, I found that  it can send spam by alias account,
for example  alias account is  all@mail.com, it includes a1@mail.com, a2@mail.com, a3@mail.com
it can connect to mail server by  all@mail.com (alias account) and then send mail to himself,
so a1@mail.com, a2@mail.com, a3@mail.com will receive the spam mail.

Does anyone have good ideas to solve it?

Thanks a lot.