Warning: this function only works in ISPConfig 3.2.3 and above We have created a new system to process custom config for Postfix and Dovecot. In version prior to 3.2.3, you had to use a custom config template which would overrule the whole file. If you wanted to change the setting for "setting b", you would have to put settings a, b, and c in there, otherwise you would hold a broken config. From now on, you can put custom lines for Postfix in /usr/local/ispconfig/server/conf-custom/install/postfix_custom.conf.master. When updating ISPConfig (to 3.2.4 or higher), the lines in this file will overrule the settings set in ISPConfig's config templates. Custom lines for Dovecot go in /usr/local/ispconfig/server/conf-custom/install/dovecot_custom.conf.master. They will be placed in a separate file (/etc/dovecot/conf.d/99-ispconfig-custom-config.conf) - but don't edit this file manually, as it will be overwritten when updating. You can apply changes to the dovecot config manually without updating by running Code: cp /usr/local/ispconfig/server/conf-custom/install/dovecot_custom.conf.master /etc/dovecot/conf.d/99-ispconfig-custom-config.conf systemctl restart dovecot If you start using conf-custom templates, make sure you check what has changed in the ISPConfig templates (important changes will be noted in the release notes) so you can change your custom template if necessary. With this change, I hope the number of people who upgrade and let the script reconfigure their services increases, to prevent insecure/broken systems.