We were able use it in conjunction with our existing email systems so we didn't have any problems switching over from one service provider/email platform (Asterisk) to another(e1campustu). The software itself was very easy to install but had some bugs along its way which required support services as well - just be patient! Also I believe they are working out issues around their integration into other vendors' products such as Microsoft Exchange Server & MS Outlook etc., however no ETA has been given at this stage of writing these reviews since last update by them regarding same few months ago.