Help Not able to send or receive mms.

[isaemm]

My girlfriend's phone just suddenly stopped being able to send or receive mms/picture messages. No new apps have been installed, tried battery pulls but its still not working. When she tries to send them, her phone will say "sending" but the message never gets sent, it will just stay that way until she deletes the message. And when she gets a picture message, it will say "downloading" but it never goes through to her. Any one have any ideas?