Issue: In the Processes Tab of Task Manager, store.exe’s physical memory is allocating too much memory.
Resolution: You may tweak the cache size of the Exchange Server’s Information Store to prevent the store.exe’s physical memory size to increase. To do this process, click on Start button and type ADSIEDIT.msc, press enter.
Navigate to the Configuration> CN=Services> CN=Microsoft Exchange> CN= First Organization> CN=Administrative Groups> CN=Exchange Administrative Groups> CN=Servers [SERVERNAME]> > InformationStore
Right click Information Store and set the following to 72000 then Click OK to save the setting.
If adjusting the cache size didn’t help to resolve the issue, verify that the Exchange Server has the latest Service Packs and Window Updates.