Something may be WRONG in the current update process for ispconfig3. I updated ispconfig3 (2 servers) today to 3.29-p1 a couple of hours ago and it apparently changed BOTH my server main.cf files as follows: The postfix main.cf file was CHANGED ( I suppose during configurations ) FROM smtpd_client_restrictions = check_client_access proxy:mysql:/etc/postfix/mysql-virtual_client.cf, permit_inet_interfaces, permit_mynetworks, permit_sasl_authenticated, reject_rbl_client b.barracudacentral.org, reject_unauth_pipelining , permit TO smtpd_client_restrictions = check_client_access proxy:mysql:/etc/postfix/mysql-virtual_client.cf, permit_inet_interfaces, permit_mynetworks, permit_sasl_authenticated, reject_rbl_client zen.spamhaus.org, reject_unauth_pipelining , permit The zen.spamhaus.org comes back as open resolver and BLOCKED all incoming email (HUNDREDS in an hour!), returning these errors: Mar 3 12:08:50 server postfix/smtpd[13160]: NOQUEUE: reject: RCPT from relay11.christianbook.com[208.68.79.111]: 554 5.7.1 Service unavailable; Client host [208.68.79.111] blocked using zen.spamhaus.org; Error: open resolver; https://www.spamhaus.org/returnc/pub/2400:cb00:618:1024::a29e:b907; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<relay11.christianbook.com> Error stopped immediately by changing the reject_rbl_client back to barracuda. Better check it out! Thankful for ISPCONFIG3, Richard Bartz
This means you have spamhaus configured as RBL in ISPConfig: System > Server config > server1.example.com > Mail > Real-time Blackhole List.
As @Th0m mentioned, there is nothing wrong with the update process. You seem to manually have edited postfix main.cf instead of setting the realtime blacklist in ISPConfig server config settings.
Thank you guys, I have changed the main.cf manually occasionally over time. I did not know that there were postfix settings in the server config settings. I am not certain how the server setting became zen.spamhaus.org. I used that in the past but I deleted zen.spamhaus.org manually from the main.cf after they stopped serving the RBL last year. Thanks again, Richard