postfix.conf - put the options line-by-line instead of one single line
Instead of having a single line per option in postfix.conf, it would make it better readable if the arguments are line by line, e.g.: instead of
smtpd_helo_restrictions = reject_invalid_helo_hostname, permit_mynetworks, check_helo_access regexp:{config_dir}/helo_access, permit_sasl_authenticated, reject_non_fqdn_helo_hostname, check_helo_access regexp:{config_dir}/blacklist_helo, {reject_unknown_helo_hostname}, permit
make it
smtpd_helo_restrictions = reject_invalid_helo_hostname,
permit_mynetworks,
check_helo_access regexp:{config_dir}/helo_access,
permit_sasl_authenticated,
reject_non_fqdn_helo_hostname,
check_helo_access regexp:{config_dir}/blacklist_helo,
{reject_unknown_helo_hostname},
permit
This would make it also better comparable after an upgrade of ISPconfig and/or the server. (e.g. for the users with etckeeper to keep track of any configuration changes).