======== Required information ====
- iRedMail version: iRedMail-0.8.5
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  MySQL
- Linux/BSD distribution name and version:  RHEL
- Related log if you're reporting an issue:
====

Hello,

Problem Statement

I have installed iredmail on rhel hosted on an Amazon cloud server. However I am able to login to the web control panel, create a domain etcc… and add users. For one user I have added, I am able to send an email out, but when I reply to this email (i.e sending it back to the originating address), I get

Delivery to the following recipient failed permanently:

     help@isdcgroup.in

Technical details of permanent failure:
DNS Error: DNS server returned answer with no data

----- Original message -----

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20120113;
        h=mime-version:date:message-id:subject:from:to:content-type;
        bh=JHbjBQjciubCFQdDFuIBIqHx4P420Fa29jj2BNxuHUg=;
        b=s5szCxdsrnhnFeyTOVe48iglvp2BNhR9oE96sWXESsZvZ0gGZ/YCB5N6vjAQxzQMmR
         ooz1daSNrbYW3fXE2SWy1BlVTrLRQW8vmXTdCDTH+PEUTzc0sWpLz8A6XhDocL3IWLJU
         MXhP0BE2S4TNCrH597R5e21aW75MBwLqWbHgMARP+i5AXk4q1NXvJiAjUdtUyDBtnNZC
         nntRLi2EKy/m6PQ9RYdDXE6NLsnUo0T8l+Ts8rPYVQthN6AINuK6ZqxdIb/UbUZYlDMY
         8DVmH+Xs+Q8NxMVYmHUVQ3qKL9l8ZVoFa8SCRcxrAhSXppFRvnC+Mkw1KfTf/aCADmai
         wtNQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=google.com; s=20120113;
        h=mime-version:date:message-id:subject:from:to:content-type;
        bh=JHbjBQjciubCFQdDFuIBIqHx4P420Fa29jj2BNxuHUg=;
        b=IM41EPamnl+UWfEqyUxu9hrqOPJ8YE/cw/BNgXpGM5lBKdzL/Ahpx9HmMPJYU/QsdP
         CDwQJwOKlM+TADPHN6bXycaB0iT4Q86gk2NPKsbB1pBS7wFDjL8R6wFBmnNe0zMTjwNd
         0Er7aIRsWzo78kRttJOMT/bfIu7BJHOWrSEOlrnS+VG0MXy9uQw5hogYq+CzHE0ezeaB
         mVPoecq9RQ+l+u2KzoNeV5z4jHbf3KHrVSND5m50vdIPfl3+E1Tyo5qHYhAzJX/qEqc4
         JqPkbBWEIpoV7uW+zhQNYzNRl4gSDax/BK3E0T9+Ayp6GPI6jzxlX7nW1GirSZKJ9Aog
         pflw==
MIME-Version: 1.0 

What I have tried to resolve this issue

After installing the application, I had tried changing my hostname. I did the following changes

Changed the hostname, edited the following files, With this my hostname is kept as mail.isdcgroup.com

/etc/hosts
/etc/sysconfig/network

I wrote to amazon to set my reverse dns and the reverse DNS is set correctly

[root@mail ~]# dig mail.isdcgroup.in

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6 <<>> mail.isdcgroup.in
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20517
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;mail.isdcgroup.in.             IN      A

;; ANSWER SECTION:
mail.isdcgroup.in.      28800   IN      A       54.225.88.30

;; Query time: 16 msec
;; SERVER: 172.16.0.23#53(172.16.0.23)
;; WHEN: Wed Jul 24 07:18:29 2013
;; MSG SIZE  rcvd: 51

[root@mail ~]# dig -x 54.225.88.30

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6 <<>> -x 54.225.88.30
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 65159
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;30.88.225.54.in-addr.arpa.     IN      PTR

;; ANSWER SECTION:
30.88.225.54.in-addr.arpa. 300  IN      PTR     mail.isdcgroup.in.

;; Query time: 10 msec
;; SERVER: 172.16.0.23#53(172.16.0.23)
;; WHEN: Wed Jul 24 07:19:40 2013
;; MSG SIZE  rcvd: 74

I have set the A record, MX record and TXT record in to my DNS (of my domain vendor )

Please see attachment1 for screenshots

The txt record setting was as per the suggestion on a google support post, I had just done the changes and I am assuming my dns update will take some time as the below out put run just now returns

[root@mail ~]# amavisd -c /etc/amavisd/amavisd.conf testkeys
TESTING#1: dkim._domainkey.isdcgroup.in      => invalid (public key: not available)

Below is my “netstat –tap” output..

[root@mail ~]# netstat -tap
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 *:submission                *:*                         LISTEN      8166/master
tcp        0      0 isdcgroup.in:distinct32     *:*                         LISTEN      7999/amavisd (maste
tcp        0      0 *:pop3                      *:*                         LISTEN      1373/dovecot
tcp        0      0 isdcgroup.in:10031          *:*                         LISTEN      1646/policyd
tcp        0      0 *:imap                      *:*                         LISTEN      1373/dovecot
tcp        0      0 *:sunrpc                    *:*                         LISTEN      922/rpcbind
tcp        0      0 *:33620                     *:*                         LISTEN      952/rpc.statd
tcp        0      0 *:ssh                       *:*                         LISTEN      935/sshd
tcp        0      0 isdcgroup.in:ipp            *:*                         LISTEN      1020/cupsd
tcp        0      0 *:smtp                      *:*                         LISTEN      8166/master
tcp        0      0 *:sieve                     *:*                         LISTEN      1373/dovecot
tcp        0      0 isdcgroup.in:cbt            *:*                         LISTEN      1631/python
tcp        0      0 *:imaps                     *:*                         LISTEN      1373/dovecot
tcp        0      0 *:pop3s                     *:*                         LISTEN      1373/dovecot
tcp        0      0 isdcgroup.in:10024          *:*                         LISTEN      7999/amavisd (maste
tcp        0      0 isdcgroup.in:10025          *:*                         LISTEN      8166/master
tcp        0      0 *:mysql                     *:*                         LISTEN      1349/mysqld
tcp        0      0 isdcgroup.in:mysql          isdcgroup.in:51483          ESTABLISHED 1349/mysqld
tcp        0      0 isdcgroup.in:51467          isdcgroup.in:mysql          ESTABLISHED 8001/amavisd (ch1-a
tcp        0   1084 ip-10-164-108-135.ec2.i:ssh 115.241.190.149:49704       ESTABLISHED 7737/sshd
tcp        0      0 isdcgroup.in:mysql          isdcgroup.in:51467          ESTABLISHED 1349/mysqld
tcp        0      0 isdcgroup.in:51483          isdcgroup.in:mysql          ESTABLISHED 8002/amavisd (ch1-a
tcp        0      0 *:46187                     *:*                         LISTEN      952/rpc.statd
tcp        0      0 *:sunrpc                    *:*                         LISTEN      922/rpcbind
tcp        0      0 *:http                      *:*                         LISTEN      1505/httpd
tcp        0      0 *:ssh                       *:*                         LISTEN      935/sshd
tcp        0      0 localhost6.localdomain6:ipp *:*                         LISTEN      1020/cupsd
tcp        0      0 *:https                     *:*                         LISTEN      1505/httpd

To test my MX record updation, I tested my SNMP connection using mxtoolbox.com. Below is the output from the tests..

Attachment2 and Attachment3

However I am getting an connection lost in the SMTP transcript which I am unable to comprehend.

I am not able to hit at any point beyond this and need help in figuring out. Please extend your help with troubleshooting tips or redirect me to posts which has been previously raised for this issue (I could find only a recent one and I have done all the troubleshooting mentioned in there)