Q: I have an iphone 3, I'm not receiving some messages sent to me. At the moment it seems to only be from one person. They receive my messages fine, and their iphone says that their message has been sent to me. Help!

Hey cindidc,

Thanks for the question. I understand you are unable to message a specific contact. The following resource provides troubleshooting information for this symptom:

If you still can't send or receive an iMessage, follow these steps

 

1. Make sure that the contact trying to message you isn't blocked in Settings > Messages > Blocked.

 

2. Make sure that the contact you're trying to send a message to is registered with iMessage.

 

3. If the issue occurs with a specific contact or contacts, back up or forward important messages and delete your current messaging threads with the contact. Create a new message to the contact and try again.

 

4. If the issue occurs with a specific contact or contacts, delete and recreate the contact in the Contacts app. Create a new message to the newly created contact and try again.

 

5. Back up and restore your device as new.

iOS: Troubleshooting Messages

http://support.apple.com/kb/TS2755

Thanks,

Matt M.