Microsoft Office troubleshooting.
.. Really depends on what the issue is that is being experienced. If they are getting errors in their outlook you could start with a repair as the least intrusive thing to do (go to the help menu at the top and choose repair). But there might be some switches you want to run first again depending on the issue. If this is a POP3 account you can try repairing their .pst using scanpst. If all switches and repairs fail, remove and re-add their outlook profile. If it is a POP3 account you will need to migrate all the mail out of the old pst into the new one. If an exchange account this won’t be necessary. These should give you some things to start with anyway.