Who I have the same questioned this topic

Recently I switched to Verizon prepaid from At&T. Since that day I have been unable to send pictures of gifs to my friends and family members who do not use iPhone (iMessage).

When I try to send a pic/gif to a user that has green messages, the progress bar moves very slow and eventually I get an error message that says the message is "not delivered".

This doesn't happen with iMessage users. Those go through every time.

Very frustrated! I have tried hard resetting the phone, resetting the network settings and updating the phone... still no luck.

Please help!