I located the follwoing Q & A on the Apple site. I have the same issue and cannot read the Verizon iPhone 4s/5 iOS 6 text messages on my Verizon Galaxy S III. Has anyone identified a solution?
(Q) A friend just updated his iPhone 4 to iOS 6, and now the texts he sends to my e-mail address are sent as a .txt attachment (titled "text_0.txt") instead of in the body of the e-mails. This is a problem, since I can't open the .txt attachments on my Kindle Keyboard. Any ideas how he can get the messages back in the body of the e-mails I receive from him?
(A) I just received the below from Verizon today:
FREE VZW MSG-DO NOT REPLY: The issue with the text messages on iOS 6 has been escalated to Apple. I will contact you when I have more information.