LinuxQuestions.org - postfix configure problem

dear all,

I have two mail server running with postfix and dovecot for pop3.
dns recoreds for them are like follows,

aaabbb.net MX preference = 10, mail exchanger = smtp.aaabbb.net
aaabbb.net MX preference = 50, mail exchanger = mail.aaabbb.net

and all mail users are created in mail.aaabbb.net server with mail box.
and smtp server only for mail transfer.

my mail.aaabbb.net servers postconf are like follows,

[root@mail postfix]# postconf -n
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
debug_peer_level = 2
default_rbl_reply = $rbl_code Service unavailable; $rbl_class [$rbl_what] blocked using $rbl_domain${rbl_reason?; $rbl_reason}
header_checks = regexp:/etc/postfix/header_checks
html_directory = no
inet_interfaces = all
mail_owner = postfix
mail_spool_directory = /var/spool/mail
mailbox_size_limit = 1048576000
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydomain = aaabbb.net
myhostname = mail.aaabbb.net
mynetworks = 168.100.189.0/28, 127.0.0.0/8, xx.xxx.xxx.0/21, xxx.xx.xx.0/20
myorigin = aaabbb.net
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES
recipient_delimiter = +
sample_directory = /usr/share/doc/postfix-2.3.3/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_invalid_hostname, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unverified_recipient, reject_unauth_destination, reject_rbl_client zen.spamhaus.org, reject_rbl_client cbl.abuseat.org, reject_rbl_client bl.spamcop.net, permit
transport_maps = hash:/etc/postfix/transport
unknown_local_recipient_reject_code = 550
[root@mail postfix]#

Now problem is that, when i send any mail to same domain user or any other sender send me from other domain that mail returned to sender and shows

error "Diagnostic-Code: smtp; 554 5.4.0 Error: too many hops".

What should i do now?? this is very urgent for me.

Thanking you,

Newbie