I have a few customers that we have upgraded from previous versions to 9.1 These installs have used and are still using UMS with exchange 2010. The thing about it is that the sites were working flawlessly with UMS for years before the upgrades. The upgrades are complete to server editions some are 9.1.2, 9.1.3, and 9.1.4. but what is happening is UMS works for days then just stops. You can go back in and restart the services in the system and it starts working again. Any thoughts? The only common piece is that they are now using the windows vmpro mapi service where as before they were all vmpro on windows servers.