Do messages send from the Apple ID or the device itself?

I'm trying to avoid sending a message that i deleted before i turned the wifi off on my iPod. I turned iMessage off and used a different device for iMessage. I just created a new Apple ID hoping that it wouldn't send the message, and after signing in, I saw that the conversations from my other Apple ID were still there and just turned the wifi and iMessage off just in case. So my question is, if I turn on iMessage, will the message send from the new ID/continue sending from the other ID, or will it send regardless of which Apple ID you're signed into?