I know ISPC uses mysql and this isn't to interface with ISPC in any way. My goal is to implement a shared addresss book for my client pc's who use thunderbird and outlook (not webmail, although I assume roundcube could also access it). This doesn't need to interface or use the ISPC users info at all, it can just be a standalone setup on the ISPC server. My understanding is that an LDAP server would work....yes/no? I also just found https://entic.net/CF Cloudface but I'm not sure if it's any good. since I'm keeping the administration separate from ISPC maybe that's an easier way to go??? I'd rather keep it on my own server though. Any thoughts or help would be appreciated.