Previously I have tried to modify Postfix smtpd_recipient_restrictions from ISPConfig Panel, but the changes have not appeared in Postfix main.cf file. So I have modified that file myself directly. Now I see that ISPConfig update changes main.cf, adding reject_rbl_client zen.spamhaus.org and on one of the e-mail servers removing the three RBL's I added (that spamhaus does not work for me, I am not subscribed). Is is possible to set smtpd_recipient_restrictions from Panel? If not, can I protect my changes from being overwritten?