I changed postfix config(file master.cf.in) to only listen port 587 for mail submission, everything is ok send/receive etc.. only problem now is reject_rbl_client fails to connect to any RBL server.

error log:

Mar 2 13:06:00 mx postfix/smtpd[31627]: warning: 74.70.38.70.b.barracudacentral.org: RBL lookup error: Host or domain name not found. Name service error for name=74.70.38.70.b.barracudacentral.org type=A: Host not found, try again
Mar 2 13:06:00 mx postfix/smtpd[31627]: warning: 74.70.38.70.zen.spamhaus.org: RBL lookup error: Host or domain name not found. Name service error for name=74.70.38.70.zen.spamhaus.org type=A: Host not found, try again
Mar 2 13:06:00 mx postfix/smtpd[31627]: warning: 74.70.38.70.bl.spamcop.net: RBL lookup error: Host or domain name not found. Name service error for name=74.70.38.70.bl.spamcop.net type=A: Host not found, try again
master.cf.in original / listening port 25/587 for mail submission

smtp inet n - n - - smtpd
465 inet n - n - - smtpd
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
submission inet n - n - - smtpd
-o smtpd_etrn_restrictions=reject
-o smtpd_sasl_auth_enable=%%zimbraMtaSaslAuthEnable%%
-o smtpd_client_restrictions=permit_sasl_authenticate d,reject
-o smtpd_tls_security_level=%%zimbraMtaTlsSecurityLev el%%
master.cf.in modified listening only port 587 for mail submission

smtp inet n - n - - smtpd
465 inet n - n - - smtpd
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
587 inet n - n - - smtpd
-o smtpd_etrn_restrictions=reject
-o smtpd_sasl_auth_enable=%%zimbraMtaSaslAuthEnable%%
-o smtpd_client_restrictions=permit_sasl_authenticate d,reject
-o smtpd_tls_security_level=%%zimbraMtaTlsSecurityLev el%%
smtp inet n - - - - smtpd
-o smtpd_enforce_tls=no
-o smtpd_sasl_auth_enable=no
Any ideas?!