Linux Mail Server Setup and Howto Guide

Hi have a postfix server running on rhel 5 with the following configuration (postconf -n) output -

alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
broken_sasl_auth_clients = yes
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
debug_peer_level = 2
disable_vrfy_command = yes
html_directory = no
inet_interfaces = all
mail_owner = postfix
mailbox_command = /usr/bin/procmail -f- -a "$USER"
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
message_size_limit = 15728640
mydestination = kelltonsecurities.com mail.kelltonsecurities.com
myhostname = mail.kelltonsecurities.com
mynetworks = 127.0.0.1
myorigin = kelltonsecurities.com
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES
sample_directory = /usr/share/doc/postfix-2.3.3/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_tls_note_starttls_offer = yes
smtp_use_tls = yes
smtpd_banner = Hi !! Nice to meet you
smtpd_delay_reject = yes
smtpd_helo_required = yes
smtpd_sasl_auth_enable = yes
smtpd_sasl_path = private/auth
smtpd_sasl_type = dovecot
smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/access
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_auth_only = no
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
smtpd_use_tls = yes
tls_random_source = dev:/dev/urandom
unknown_local_recipient_reject_code = 550
[root@mail postfix]#

I want to configure this server as an smtp relay for another server (10.10.10.2)

To do this I have the following in our relay smtp server (10.10.10.6)-

1)

in /etc/postfix/access file -

10.10.10.2 RELAY

2)

/etc/postfix/main.cf -

smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/access

3)

executed -

postmap -c /etc/postfix hash:access

service postfix restart

4)

I have the following in 10.10.10.2 (which will relay mail through 10.10.10.6)

in /etc/mail/sendmail.cf -

DSmail.kelltonsecurities.com

After that I tried to send mail from 10.10.10.2 (using telnet 10.10.10.2 25 command)

The mail is not going through the smtp relay (10.10.10.6) and I am getting the following in /var/log/maillog in 10.10.10.2 system -

Apr 19 16:22:38 kellton sendmail[12485]: o3JApr79012485: from=atanu@keltonsec.com, size=10, class=0, nrcpts=1, msgid=<201004191052.o3JApr79012485@kellton.keltonsec.com>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Apr 19 16:22:38 kellton sendmail[12487]: STARTTLS=client, relay=mail.kelltonsecurities.com., version=TLSv1/SSLv3, verify=FAIL, cipher=DHE-RSA-AES256-SHA, bits=256/256
Apr 19 16:22:38 kellton sendmail[12487]: o3JApr79012485: to=atanu.banerji@gmail.com, delay=00:00:12, xdelay=00:00:00, mailer=relay, pri=120010, relay=mail.kelltonsecurities.com. [10.10.10.6], dsn=5.7.1, stat=Service unavailable
Apr 19 16:22:38 kellton sendmail[12487]: o3JApr79012485: o3JAqc79012487: DSN: Service unavailable

Please help