I too have this same problem with my S3 and my Wife's G Note. I never had this happen with my S2. I have left my PC settings to leave read emails or deleted on the server for 5 days. I did this because of a Crash and many important Business emails were lost so now they will delete after 5 days...
Re: Straight talk apn settings for at&t samsung galaxy s3
My Wife's crappy Merit died. ST took 2 weeks to replace it under warranty. I bought her a used Galaxy Note and I fought all the other APN settings. This one finally worked! Thanks for the info Yamataz!