At&t Wireless Phone Error - Your Text Message Cannot Be Sent

Thanks wallpaperama...you described what is happening exactly. Just deleted all saved messages and deleted messages and it fixed my problem

I am getting the same message, but I am not getting any message about lack of memory.
https://www.wallpaperama.com/forums/_amxawx.html

you are getting this error because your phone doesnt have any more space to save your data. in other words, you need to delete some old files to make more room.

if you restart your phone, you will get a message telling you that your space is running low and you should delete old files.

if i were you, i would upgrade, or backup your old data on your pc and clear all the file stored in your phone. and you wont have this problem.