> postfix/smtpd[24986]: warning: hostname server17-ams1.internet-census.org
> does not resolve to address 107.6.163.34: Name or service not known
This is a type 4 error (the name->address mapping does not exist).
> postfix/smtpd[24986]: connect from unknown[107.6.163.34]
> postfix/smtpd[24986]: NOQUEUE: reject: CONNECT from unknown[107.6.163.34]:
> 450 4.7.25 Client host rejected: cannot find your hostname, 107.6.163.34];
Postfix was unable to determine the remote SMTP client hostname.
This error message is sent to the remote SMTP client. Error details
are not made available to the remote SMTP client. Error details are
logged only. Then, the local system administrator can deal with it.
Wietse
