As far as I know, iMessages are saved with your Apple ID. This means that whatever email you use for your Apple ID is associated with everything: your apps, any money you've added to iTunes, your iCloud backups, app data, and, of course iMessages that you receive. You can't add multiple iMessage emails to an Apple device as that device can only have one Apple ID on it. You'd need to sign out of your old Apple ID and re-sign in to a new one which would take a lot of hassle and would not be automatic.
Your AppleID is the one that it defaults to. However, you can create email and sign in to the Apple default mail app with new address. Once that’s done, go into Settings>Messages>Send&Receive. There will be your phone and email addresses attached to Apple Mail app. Select the ones you want to use. You can select one or all.
Comments
Hello, Do you mean a
Hello, Do you mean a different e-mail than what your apple ID is? Do you already have an e-mail address set up, or will you need to do that?
Yes I already have the Maine one
Yes, I need a second one separate from my personal email. I don’t want everything going to that one.
Different Email
As far as I know, iMessages are saved with your Apple ID. This means that whatever email you use for your Apple ID is associated with everything: your apps, any money you've added to iTunes, your iCloud backups, app data, and, of course iMessages that you receive. You can't add multiple iMessage emails to an Apple device as that device can only have one Apple ID on it. You'd need to sign out of your old Apple ID and re-sign in to a new one which would take a lot of hassle and would not be automatic.
Email
Your AppleID is the one that it defaults to. However, you can create email and sign in to the Apple default mail app with new address. Once that’s done, go into Settings>Messages>Send&Receive. There will be your phone and email addresses attached to Apple Mail app. Select the ones you want to use. You can select one or all.
You'll need to make a new address
It sounds like you will need to make a new address, then sign into that one in the messages in settings.