If you upgrade MobileX and use Office 365 and move from say
then you will need to uninstall the MobileX app on Outlook 365 and re-install.
Each client will also need to clear their caches depending on where they work.
With Outlook Web Access (OWA) on chrome they will have to clear their cache.
If using the Outlook client users will have to clear their IE or EDGE cache (depending on the version on outlook-newer versions use EDGE).
Both web.config settings must be set for the file email feature to work:
"GatewayCRMPath" and "CRMCodedPath"
To clear the client cache: