Why can’t Motorola A3100 send text messages?

Please be specific. If the number contains 12593, it cannot be sent!

There is an enter key on the sending page to import the phone book, but please note that if the imported number is 12593, you must change it in the phone book and then import it, or directly select the number to enter the number here. This is OK. Everything else about this machine is good, except that it cannot remove 125963 when writing, which is quite annoying!