MMS (Multimedia Messaging Service) is an older method for sending multimedia over text messages that doesn't always work as smoothly as newer messaging apps. There are many reasons why MMS messages might not work on Android, including attachment size limits set by carriers and recipient's carrier limitations. To fix the issue, one can check the attachment size, restart the phone, check the network connection, turn on mobile data, toggle auto-download MMS, and clear data in the Messages app. Understanding what MMS is and how it differs from other protocols like SMS can also help businesses engage users over MMS. Twilio offers a reliable messaging partner for all channels, including sending and receiving MMS messages with its Programmable Messaging API, allowing developers to speed up the process of adding account notifications and verifications to their applications.