Hello,

We have freshly installed iRedMail with the following setup (replaced live details with the dummy values)
iRedMail server (192.168.1.15) => added a domain "example.com" and created 2 accounts which are: test@example.com, test100@example.com.
example.com => MX record pointed to postfix proxy server (server.mailproxy.com)
In postfix:
              test@example.com => pointed to iRedMail server
              test100@example.com => pointed to Exchange server

Configured all the basic settings in iRedMail and postfix. Present condition is:

Sending email from "test@example.com" (iRedMail account) delivers to internal and external email accounts. The account can also receives emails just fine.

Sending email from "test100@example.com" reaches to external email accounts, but not to test@example.com. But receiving is fine.

Getting the following bounce email when sending to test@example.com:

==
Delivery has failed to these recipients or groups:
test@example.com
Your message wasn't delivered due to a permission or security issue. It may have been rejected by a moderator, the address may only accept e-mail from certain senders, or another restriction may be preventing delivery.

The following organization rejected your message: 192.168.1.15.

Diagnostic information for administrators:
Generating server: server.mailproxy.com

test@example.com
192.168.1.15 #<192.168.1.15 #5.7.1 smtp; 553 5.7.1 <test100@example.com>: Sender address rejected: not logged in> #SMTP#
==

Please not that I can send email from root@ mailproxy server to test@example.com using the mailproxy server shell without any problem.

***************************************************
- iRedMail version: 0.8.5
- Pro installed: iRedAdmin-Pro-MySQL-1.7.0-py26
- Backend: MySQL
- Linux distribution: CentOS 6.3
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Please help.