Starting from Explorer for ArcGIS 17.1.1, users can create and share markups; these markups can be shared directly with other Explorer for ArcGIS users or with other members in an organization through ArcGIS Online or Portal for ArcGIS.
The following are three possible methods to share markups in Explorer for ArcGIS:
Note: This method requires Level 2 Named User access in Portal for ArcGIS or ArcGIS Online. For more information, refer to ArcGIS Help: Levels, roles, and privileges.This method exports the markup to a Portal for ArcGIS or ArcGIS Online account. The markup layer or feature collection is exported to the My Content tab, and can be added to the web map. However, the items are not automatically added to the web map. This method is often used when sharing markups from the field to the organization (field-to-office).