[texaslonghorn5]

Maybe I am missing something obvious/important. Google Messages delay send will not send the message if the phone is off/disconnected. What's wrong with Apple Messages setting up delayed messages just like that? You said reliability. But Google Messages delay has worked 100% of the time for me and I've never had a situation where the phone was off when it needed so maybe I am the wrong person to ask.

Is there a way to have the timestamp part be unencrypted and the message be encrypted or does that violate end to end policy?

Though I like being able to cancel/edit until the send deadline so from my perspective it's best to keep on the sender device as long as possible and send only at the last possible second.

[MBCook]

But iMessage is synced between devices. So if I delay a send on my iPhone and lose network, my other Apple devices know enough they could still send it.

Should they (I asked to send) or not (‘sending’ device offline)?

[jeroenhd]

If it's E2EE, why not send the message with a timestamp at which the server should approximately process the message? If it's well encapsulated/encrypted, it shouldn't matter that the message is on the server for a while.