Lately I've been having trouble receiving texts on my iPhone; sometimes they are never received, sometimes they are delayed for hours, sometimes they are received normally, sometimes they are received only after sending a text message (sending the message results in a several seconds wait). I've done a hard reset, I've done a restore, I've update my iOS to 5.1.1, I've called Verizon. Verizon hasn't been able to help.
I use messaging all the time, so I understand how important it is for this feature to work correctly! I'd like to ask a couple of questions to get to the root of the issue.
-Are you using messaging or iMessage with the iPhone?
-Is this happening with all messages, or a specific number of contacts?
-Your post mentions sending messages, Are you able to send all of your messages with no problem?
Please try a soft reset of your device as a troubleshooting step. Follow this link for the steps: