Question:

What are the criteria for identifying a message as SMS or MMS when it is not obvious from the content or length? For example, I sent a message that was less than 160 characters and had no attachments, but the recipient said it was an MMS. How did they know? Does it have anything to do with the CRS setting or the phone model?

Answer:

How to tell if a message is SMS or MMS

SMS and MMS are two common types of messages that you can send and receive on your phone. SMS stands for Short Message Service, and MMS stands for Multimedia Messaging Service. SMS messages are limited to 160 characters and can only contain text, while MMS messages can be longer and can include images, videos, audio, or other media attachments.

Usually, you can tell if a message is SMS or MMS by looking at the content or length of the message. If the message is longer than 160 characters or has any attachments, it is most likely an MMS. However, there are some cases where the message type is not obvious from these criteria. For example, you might send a message that is less than 160 characters and has no attachments, but the recipient says it is an MMS. How did they know? Does it have anything to do with the CRS setting or the phone model?

The answer is yes, it does. There are some factors that can affect the message type, even if the content or length does not. These factors include:

• CRS setting: CRS stands for Chatbot Response System, and it is a feature that allows you to interact with chatbots using text messages. If you enable CRS on your phone, any message that you send to a chatbot number will be converted to an MMS, regardless of the content or length. This is because CRS messages use a special format that requires more data than a regular SMS. You can check if CRS is enabled on your phone by going to Settings > Messages > Chat Features. If you want to send an SMS to a chatbot number, you can disable CRS temporarily or use a different messaging app.
• Phone model: Different phone models may have different standards for sending and receiving messages. Some phones may automatically convert an SMS to an MMS if the message contains certain characters, such as emojis, symbols, or foreign languages. Some phones may also have a lower limit for the SMS character count, such as 70 or 140, instead of 160. This means that a message that is less than 160 characters on your phone may be more than 160 characters on the recipient’s phone, and thus be sent as an MMS. You can check the SMS character limit on your phone by going to Settings > Messages > Text Message Length.
• Carrier settings: Different carriers may have different policies for charging and delivering messages. Some carriers may charge more for MMS than SMS, or may not support MMS at all. Some carriers may also compress or resize the media attachments in MMS messages, which can affect the quality and appearance of the message. You can check the carrier settings on your phone by going to Settings > Messages > Carrier Services. If you want to avoid extra fees or quality issues, you can use a different carrier or a different messaging app.

These

are some of the criteria for identifying a message as SMS or MMS when it is not obvious from the content or length. By being aware of these factors, you can avoid confusion and frustration when sending and receiving messages on your phone.