Why can't Apple 4S send and receive MMS?

There should be something wrong with the MMS settings, which can be set according to the following methods:

1) Check the upper left corner of the iPhone display to make sure that you are in the strong signal area, and make sure that the flight mode is off, the cellular data switch is on, and it is already being set >; Turn on the MMS switch in SMS. If the current location signal is weak, please try to move to another location. If you are indoors, try going outside or moving to the window.

2) Whether the 2)USIM card supports sending MMS and whether the business status is normal.

3) Try to send plain text multimedia messages, and don't send any videos, photos or voice memos (fill in short messages in the subject field and send them in text) to the appropriate mobile phone.

If you can send a plain text MMS, you can prove that the customer's MMS function is normal, and then check whether it is the picture format or size.

Note: For example, before IOS4.2 1, you can't send screenshots over 200K, and a red exclamation mark will be displayed. Unicom SIM card is recommended to be upgraded to the latest IOS version before it can be sent normally.

Unicom users can send screenshots and photos taken in the latest IOS4.2 1 in the form of MMS, regardless of the size, without any problems.

4) If it is international roaming, please make sure it is in Settings >; "General" > data roaming in the network has been turned on, and you can send or receive MMS content.

5) Some operators are allowed to edit APN (access point name), which may cause MMS to fail to work normally. Please check whether the manually entered MMS APN parameters are correct.

6) restart the iPhone.

7) restore network settings: tap settings > general > restore > restore network settings to restore Wi-Fi and cellular network settings.

8) Restore all settings: press Settings > General > Restore > Restore all settings.

9) Put this SIM card into other non-iPhone phones to see if MMS can be sent normally, and put it into iPhone with other WCDMA or GSM SIM cards supporting MMS function to see if MMS can be sent. If you still can't send MMS, please restore the factory settings.