For those not receiving mail after upgrade who may be hosted at Hetzner - the postfix main.cf blocklist has been reverted to zen.spamhaus.org and hence you are getting the open resolver error repeat of Febuary this year. Solution replace zen.spamhaus.org with xxxxxxxxxxxxxxxxxx.zen.dq.spamhaus.net=127.0.0.[2..11] where x is your dedicated zen sub domain. Restart postfix.
I note that ISPConfig will not accept xxxxxxxxxxxxxxxxxx.zen.dq.spamhaus.net=127.0.0.[2..11] if you attempt to replace zen.spamhaus.org is in the Server Config balckhole list. Is this a bug?
Then you must have edited postfix main.cf manually and forgot to make your changes update-safe e.g. by creating a /usr/local/ispconfig/server/conf-custom/install/postfix_custom.conf.master file. No, this kind of syntax is just not supported. You might want to use a postfix config file customization instead using /usr/local/ispconfig/server/conf-custom/install/postfix_custom.conf.master
Yes. When it happened in February one is under intense pressure getting email working again and hence having located the issue I slavishly followed Spamhaus' instructions. It worked and the relief could only be completed by copious malt whisky after several hours sweating. This time I looked up my notes at the time and repeated. Thank you for reminding me to update /usr/local/ispconfig/server/conf-custom/install/postfix_custom.conf.master. And thank you for 3.3!
I don't have that file. I presume I just copy a working main.cf into it or should it be an edited main.cf?
That's why I said create the file and not edit it No., this is just a custom override file where you just add the main.cf line that you want to alter.
Can you explain what is a dedicated zen sub domain? Can also let me know which line should I add to /usr/local/ispconfig/server/conf-custom/install/postfix_custom.conf.master file?
That is a custom domain assigned to you by the spamhaus project when you pay for their service I assume. The setting in postfix are withing the "smtpd_recipient_restrictions" in form of a "reject_rbl_client domain.tld". But you don't need to do that. If you want to just disable the "zen.spamhaus.com" Blacklist do the following: 1. ISPConfig Panel -> System -> Server Config -> Your Server -> Mail 2. At the bottem somewhere you'll find "Real-time Blackhole List" = zen.spamhaus.org 3. Delete that entry
