We have an Exchange 2007 server supporting a mix of Outlook 2003, 2007, and 2010 (roughly 2000 users) in one Active Directory domain. Then there is a Domino Server supporting roughly 2500 Lotus Notes clients in a second domain. I'm not sure what version of Domino or Lotus Notes clients, but can find out. Currently there is an older Exchange 2003 server running the old Lotus Notes connector on it. We are planning on moving to Exchange 2010. This will break the 2003 connector. We can purchase the co-existance software from Quest but seems rather expensive for something that used to be free. We currently dont transfer the free/busy or calendar info between the two email systems, and at this point it is only used for mail flow and keeping our address lists synchronized.
Are there any cheaper alternatives I should consider? Is there anything else we should consider, such as scripting it in powershell? We have done imports/exports from/to csv with other exchange organizations in the past, but not to domino. The only downside there is manually going through who's already been added from the last update if you do it on a monthly or quarterly basis.