Host not found error in maillog

My clients are getting following error. how can we allow such domains?

Do I have to whitelist avs-gsa.com or mailx.mass.co.th?


Oct 24 03:10:41 linode postfix/smtpd[9844]: NOQUEUE: reject: RCPT from mailx.mass.co.th[202.149.105.4]: 450 4.7.1 <FMMASS.mass.co.th>: Helo command rejected: Host not found; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<FMMASS.mass.co.th>

 

Can you please provide the output of the command "postconf smtpd_helo_restrictions".

 

smtpd_helo_restrictions = permit_sasl_authenticated, permit_mynetworks, check_helo_access regexp:/etc/postfix/helo_access, reject_invalid_hostname, reject_non_fqdn_hostname, reject_invalid_helo_hostname, reject_unknown_helo_hostname, check_helo_access regexp:/etc/postfix/blacklist_helo
-

 

You can add the domain to /etc/postfix/helo_access and "whitelist" it that way. Like this:

Code:

/^FMMASS\.mass\.co\.th$/ OK

or if you want every subdomain too:

Code:

/\.mass\.co\.th$/ OK

 

Do I have to do postmap after that? Or restart postfix?

 

also OK or PERMIT?

 

OK ist correct. You should'nt need to reload postfix, or postmap this file as it is not used as .db. Both of the commands would'nt hurt anything, but just try the configuration i guess.