mapistub.dll is a process belonging to the MAPI program . mapistub.dll is a module containing functions used by MAPI for Windows NT.
Check that mapistub.dll is stable on your computer.

mapistub.dll should not be disabled, required for essential applications to work properly. It is highly recommended to run a FREE performance scan to automatically optimize memory, CPU and Internet settings.

Determining whether mapistub.dll is a virus or a legitimate Windows DLL depends on the directory location it executes or runs from. Click to Scan your PC including mapistub.dll to Detect any Security Threat.