Any suggestions for a CRM2Office replacement?

We were using the CRM2Office plug in for a while now. Recently the authentication server started rejecting our requests even though we purchased a lifetime license. After well over a month of trying to contact the creator we are trying to find a replacement. Does anyone know a decent replacement of CRM2Office? I see that Sugar offers an official plug in if you upgrade to a paid version of Sugar but we are hoping to stay with the CE. By the way we are using version 6.5. Any suggestions would be appreciated.