MMS not working

Check out the solution at this thread:

Can't send or receive MMS messages | AT&T Community Forums (att.com)

Good evening @AmandaR08,

Thanks for reaching out to our AT&T Community page. It would be a pleasure to assist you with the MMS messaging issue you are encountering on your Samsung Galaxy Note 20 Ultra. 

To ensure we are covering all bases please may you follow these steps recommended for your specific issue: 

• First, please visit our online troubleshooting guide. If you have not complete all steps, we advise in doing so. This guide will give you easy step-by-step directions
• Try switching SMS/MMS off and on
• If you have not checked for a system update, please check for available updates on your device: From a Home screen, touch and swipe up or down to display all apps, tap Settings > System updates > Check for system updates.

If neither of the recommended steps help. This may be a known issue. We have received notice that Samsung has identified this issue and will be sending an update to affected devices in the next 24hrs. Please update your device when prompted, to resolve the issue. Samsung is also aware that this is causing issues sending group messages/ MMS/SMS. This issue should be resolved by Samsung soon.

If you have any other questions or concerns, please do not hesitate to reach back out to us. 

Thank you for being a part of our AT&T Community

- Amber AT&T Community Specialist