Many mobile browsers have restrictions in place to keep videos from accidentally playing and without the user pressing a Play button. As of iOS 10's Safari browser and most recent versions of Chrome, an exception has been added for videos without an Audio track, or videos that have been muted.

To have the videos load muted:
  1. Go to onMessage > Website > [Site name].
  2. Select Pages & Menus.
  3. Locate the page that contains the video and click the Wrench icon next to it.
  4. Select Edit Page Content.
  5. Locate the Video block and click the Gear icon.
Edit video block settings
  1. Mark Mute Video.
Mute Video
  1. Click Save.
  2. Click Apply Changes