Issue Problem to resolve hostnames by Postfix

[Edward Dekker]

Hi,
I do have a problem to resolve hostnames by Postfix.

Beneath here i have some code to show to sove the problem.
And for now i have some difficulties to solve it.

okt 14 08:28:07 edwarddekker postfix/smtpd[14072]: warning: hostname pei-186-0-xc-lii.une.net.co does not resolve to address 186.0.90.52: Name or service not known
okt 14 08:29:26 edwarddekker postfix/smtpd[14072]: warning: hostname static-187-44-106-11.optitel.net.br does not resolve to address 187.44.106.11: Name or service not known
okt 14 08:30:22 edwarddekker postfix/smtpd[14195]: warning: hostname hosted-by.rainbownetworks.net does not resolve to address 93.174.93.228
okt 14 08:33:29 edwarddekker postfix/smtpd[14207]: warning: hostname wimax-cpe-189-208-163-224.tijbcn.static.axtel.net does not resolve to address 189.208.163.224
okt 14 08:37:04 edwarddekker postfix/smtpd[14239]: warning: hostname 179-228-162-193.user.vivozap.com.br does not resolve to address 179.228.162.193: Name or service not known
okt 14 08:41:53 edwarddekker postfix/smtpd[15968]: warning: hostname dsl-90-242.bl27.telepac.pt does not resolve to address 176.79.90.242: Name or service not known
okt 14 08:54:40 edwarddekker postfix/smtpd[16994]: warning: hostname 189-112-185-186.static.ctbctelecom.com.br does not resolve to address 189.112.185.186: Name or service not known
okt 14 09:00:52 edwarddekker postfix/smtpd[17491]: warning: hostname hosted-by.rainbownetworks.net does not resolve to address 93.174.93.228
okt 14 09:03:44 edwarddekker postfix/smtpd[17684]: warning: hostname b39af9b3.virtua.com.br does not resolve to address 179.154.249.179: Name or service not known
okt 14 09:08:48 edwarddekker postfix/smtpd[18095]: warning: hostname 179-111-207-156.dsl.telesp.net.br does not resolve to address 179.111.207.156: Name or service not known

I try to solve with this with (/etc/host.conf):

# We have machines with multiple IP addresses.
multi on

And also with (/etc/postfix/main.cf):

import_environment = MAIL_CONFIG MAIL_DEBUG MAIL_LOGTAG TZ XAUTHORITY DISPLAY LANG=C RESOLV_MULTI=on

And for now no results to solve it.
Are there someone who knows to master this situation?

 

[sbotto]

I'm having the same issue. I've seen that, for non Plesk servers, they recommend things like the ones shown here:

Problem with Postfix and DNS

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Postfix Reverse DNS Lookup: 450 4.7.1 Client host rejected

Postfix seems to be consistently rejecting mails from few servers though PTR lookup for those domains is successful. Please see log below. I have run out of ideas on what we can do to get this work...

superuser.com

None of the config parameters stated on those answers exist at my /etc/postfix/main.cf, so I don't want to just start testing things out in my production server since there are hundreds of people constantly using it.

How should I stop postfix from trying to resolve the hostname of a user that's trying to connect to it?