[mhgamer890]

I just switched to AT&T and can not send a text even with 3 bars of signal (4G LTE). I had the same issue with the S4, but on verizon network.

I can have my galaxy note 4 next to this phone and send text after text. What do i do?

[palandri]

SMS text messaging doesn't use data. Check your settings: Go to phone settings —> more… —>mobile networks —>Access Point Names

From what I am seeing, for AT&T your setting should be (but check with AT&T to make sure. I am on T-Mobile):

Name: ATT Phone
APN: phone
Proxy: Not set
Port: Not set
Username: Not set
Password: Not set
Server: Not set
MMSC: http://mmsc.mobile.att.net
MMS Proxy: proxy.mobile.att.net
MMS port: 80
MCC: 310
MNC: 410
Authentication type: None
APN type: default,mms,supl
APN protocol: IPv4
APN roaming protocol: IPv4
Bearer: Unspecified
Mobile Virtual network operator: Not set