I know I can edit postfix's config on my own in order to prevent it from using IPv6, but is there a way to do the same with ISPConfig?
Actually it is, as I already had that setting and when I upgraded to 3.1 the change was lost. That's why I'm asking if there is some better way to setup that and make ispconfig preserve it.
uhm .. why do you want your MTA not to speak IPv6? i can't really see any good reason for doing that in the first place :-D
You would do this for example when there are IPv6 network and delivery problems or when you have spam problems as blacklists are less effective on IPv6 die to the huge amount of available addresses. To make your config update safe, copy the postfix main.cf template file from install/tpl/ folder of the ispconfig tar.gz file to the folder /usr/local/ispconfig/server/conf-custom/install/
