Is there any solution for this at all. I have been having the same issue since the IOS 601 update.
There is absolutely no issue with the carrier, my phone number is set properly in iphone and the text sms work great with most of the contacts. I have this issue only for a specific few. I also checked the format in which the numbers are stored, but nothing strange anywhere.
Guess its an universal issue that needs help from apple to fix it.
That is not text messaging as in SMS/MMS so your carrier or the recipient's carrier has no bearing on this unless you or the recipient with iMessage enabled doesn't have internet access at the time. iMessages are exchanged via the internet no different from email.
Delivered not being shown for an iMessage that was successfully sent does not mean the iMessage was not delivered.
If there is a red indicator on the message indicating the message was not sent, that is different.
I have no problems whatsoever exchanging iMessages with fellow iOS device users and Mac users with iMessage enabled, so this is not a "universal" issue.
Just came back to give a quick update. I got my phone replaced because of this text sms issue. Unfortunately the issue cropped up in the new phone also. Later after many hours of investigation i found out that the real culprit is somewhere hidden when I synced the contacts with outlook.
1. I restored the phone
2. Updated to latest OS
3. Created some 10 contacts manually
4. Send SMS to the 10 contacts - Boom, they are all through without any single issue.
5. Created a new contact in outlook and did a sync with iphone.
6. Text SMS issue with the new contact created via outlook
7. I deleted the contact (created via outlook) from outlook - synced with iphone and cloud
8. Created the contact again manually (same one that i created via outlook)
9. Text SMS still remains
Does anyone know how to make iphone and cloud "forget" the contact "permanently" - may be deleting contact .still keeps some references inside the phone?
Thanks for any help.