email server like zimbra 2

PLEASE READ FIRST who can setup email server like zimbra/openxchange (openxchange community edition preferred) needed features - like outlook (emails, contacts, meetings, etc ..) - meetings directly linked to jitzu meeting and can be booked directly from the meeting for (plz check a feature video of zimbra) - multi tenant / domains - auth ads user database / with SSO from the session DO NOT BID IF YOU: 1. write me that the budget is to small 2. IF YOU HAVE NO COMMUNICATION AT ALL (no answer or very slow) highly preferred is the open xchange community edition as a base system (zimbra and open xchange doesnt offer a one time payment model, i dont pay per month and user. they offer no solution for me). than add ads connector (to get the users email and passwords), and the most tricky part will be that booking of meetings is directly with and button connected to jitzi (book a video meetings). this requires maybe some programming skills (but i am not sure how to implement such feature) please keep in mind: i have more small projects and soon i am looking for some long time agreement with somebody deep knowleged in linux, openshift, engineering, batch skripting, etc.