I have problems sending and receiving picture messages on my Apple iPhone Xs Max

Step 1 of 15

Press Settings.

Press Settings.
Press Mobile Service.
Press Mobile Data Network.
Press APN and key in wap.o2.co.uk.
Press Username and key in o2wap.
Press Password and key in password.
Press MMSC and key in http://mmsc.mms.o2.co.uk:8002.
Press MMS Proxy and key in 82.132.254.1:8080.
Press arrow left.
Slide your finger upwards starting from the bottom of the screen when you're done.
Press Settings.
Press Apps.
Press Messages.
Press the indicator next to 'MMS Messaging' to turn on the function.
Slide your finger upwards starting from the bottom of the screen to return to the home screen.

Try sending a picture message to another number.