Ok so I spent 4 hours on the phone with the Straight Talk and I finally got the correct APN settings for my Google Nexus 5 phone to send and receive MMS messages. I was really frustrating dealing with the high call volume issues that Staight Talks Customer Service experiences, but everyone I actually talked to was the typical customer service niceness. Faked, but pleasant. Here are the screen shots of my settings and Ill type them out as well. This is for the AT&T micro sim card inserted into a Google nexus 5 phone. 4.4 Android.
Name=Straight Talk APN=tfdata Proxy=not set Port=Not set
Username=not set Password=not set Server=Not Set MMSC= http://mms-tf.net
MMS proxy = mms3.tracfone.com MMS PORT=80 MCC=310 MNC=410
Authentication Type=PAP APN type=default,supl,mms,hipri APN Protocol=IPv4 APN Roaming Protocol=IPv4
Bearer= unspecified MVNO type=None
Name=Straight Talk APN=tfdata Proxy=not set Port=Not set
Username=not set Password=not set Server=Not Set MMSC= http://mms-tf.net
MMS proxy = mms3.tracfone.com MMS PORT=80 MCC=310 MNC=410
Authentication Type=PAP APN type=default,supl,mms,hipri APN Protocol=IPv4 APN Roaming Protocol=IPv4
Bearer= unspecified MVNO type=None