Why I can't send MMS

[copjake]

For the past few days my Nexus 6P keep saying Can't send MMS service not activated on network if I remove the sim and put in another phone it works fine. I tried every messing app still no luck did a factory reset start fresh no luck. PLEASE HELP!!!

 

[Tim1954]

Contact your service provider (on another phone) and have them go through their settings with you...