Time required to receive delivery receipts for international Iphone to Iphone text messages

rambo12 wrote:

Can I make an educated guess about where her phone is connected based on the amount of time it takes for a text message delivery receipt to appear in my phone?

No.

rambo12 wrote:

A few weeks ago, there was a 5 to 10 second delay, but now the delivery receipt appears within one second.

iMessage delays, if any, are caused by the internet connectivity issue.

SMS/MMS delays, if any, can be attributed to Cellular Service Provider's network.

The time for the delivery of iMessages or normal text messages depends on the network connection. In both cases, Wi-Fi or cellular network, the speed is also a factor, if photos are included, for example.

rambo12 wrote:

My iPhone is sending MMS text messages to a former friends iPhone. Everything is blue. I believe my friend's phone is connected to WIFI because SMS texts are not delivered.

If the message bubble is blue then it is not MMS but is called iMessage.

rambo12 wrote:

I am in the United States, and I don't know where my friend is. Possibly in Shanghai, possibly in the US.

For sending iMessage, you need not know the whereabouts of the receiver of the message.