How long does apple keep messages in imessage?

Not true, I've established iMessage on a new device, did not restore from a backup, and many months of old iMessages were downloaded when I began a new conversation with a person with whom I'd had a past thread. Don't spread misinformation. It's okay to say you don't know.

This has important troubleshooting and privacy implications for many people and Apple is silent on the issue.

You have no idea what you're talking about...none. In response to a subpoena, for iMessage records, Apple's response:

"iMessages are kept on Apple servers only as long as is necessary to deliver the message."

You're the one that needs to stop posting "misinformation".

So forceful! You have a source for that subpoena and a date I suppose? My Google-Fu must be weak because I couldn't find such a subpoena on the net.

By the way, that answer isn't a "no." "As long as necessary" can be along time since Apple cannot determine when you've read it everywhere you want to and so it's OK to delete.

I was able to pull iMessages from old deleted message threads on a new device. I also come home and sit at my Mac and my message conversation from the day on my iPhone becomes mirrored in iMessages on my computer, attachments and all, where I then copy the things I can't on the phone like ringtones and so on. Anyone can try this at home and I suggest you do. Where are these messages stored all day as I'm using my phone to be later mirrored on my home Mac?

I'm not seeing an error. I'm not just looking at unsent messages. Does it even matter anyway? Apple stores messages and their ToS states that they can do this, you agreed to it, and this policy can change at any time without your consent. Read it, thoroughly. I had to deconstruct it in a law class for a paper. I doubt you did this.

You are defensive but nobody is attacking Apple. Of course Apple stores messages for a long time. Why wouldn't they? Apple necessarily has access to the iMessage servers exactly the same as the servers that store your email or photo streams. There are legitimate business reasons! No one is saying they are abusing this access. This isn't even an issue but saying it doesn't happen betrays a lack of knowledge how this tech works.

If someone sent you a bunch of iMessages, maybe hundreds, and you haven't read them they aren't stored indefinitely until you read them on a device or on a Mac with your iCloud account? Can you say how long? No, you can't and neither can anyone outside of Apple and this is a changing number anyway.

You believe that once a message is sent that Apple immediately deletes it? Why would they when there's no requirement? You might check it from another device later on, Apple can't know if you've read it everywhere you want to. Syncing conversations across devices that are checked at different times requires some amount of storage of historical messages! Deleting a message immediately once sent would prevent this.

Do you thoroughly understand the technology involved? Do you have inside Apple knowledge of trade secrets?

I posted in this thread because I genuinely want to help the OP and you are speaking without evidence whereas my assertion is easily tested by the community in 10 minutes.

This is all mostly inaccurate. A more thorough discussion of iMessage cryptology is posted in the iOS 9 security white paper, summarized and linked to here:

http://techcrunch.com/2014/02/27/apple-explains-exactly-how-secure-imessage-real ly-is/

Your reply is right on target, according to my understanding (and I consult in Digital Forensics, so I know a thing or two about this). Apple doesn't not have access to the encryption keys associated with each iMessage account, therefore, they cannot retrieve the iMessages in readable format--that's the point of contention with the FBI and other Gov't agencies that don't like Apples response that they cannot decrypt the user's data, even though that data resides on their servers. My understanding is that this encryption applies to two Apple services, iMessage and FaceTime (although I'm not certain whether Apple could retrieve the metadata on the calls made or received through FaceTime, such as the caller ID/No., etc.

So the subpoena reply alluded to above, is partially correct. The information is stored on the Apple servers, but it's encrypted and therefore Apple cannot decrypt the data and turn it over pursuant to a legally authorized request.

iMessage servers do not store any messages. If someone you send an iMessage to is offline, the iMessage will temporally be stored until delivered.

Is there somewhere that Apple verifies that iMessage servers do not store ANY messages? thanks

So If the police subpoeno your records they wont see anything since you used imessage, correct?

Also how do you know this?