Today while working with new Outlook App suddenly observed that New Case option was removed from it. Little wondered and do not the reason.
After little search came to know that it was because of Read Only In Mobile user (settings -> customizations -> customize the system) was checked.
However, after enabling also it didn’t work. Below are the things we should check.
1) Read only in Mobile user should be disabled.
2) Case entity must be selected for Global Search.
If it is not visible even after setting above, follow the below steps.
1) Open IE Browser -> Tools -> Internet Options
2) General Tab -> Delete -> Settings -> Caches and databases
3) As shown in the screen shot select Dynamics.com and click on Delete and then Ok button.
4) Restart your Outlook and you will new Case option now.
Hope this helps.