Can you reuse an email after deleting an account?

To ensure you can use the email address again, get another email address from somewhere like AOL or Yahoo, and change the email address on the Apple ID that hasn't made a purchase.

Note the restrictions in the article.

Apple ID Name Change.  * 

Make sure you turn of Find My Phone before signing out of the old ID. Once signed out and Find My Phone is off, then sign in with the new ID, then turn Find My Phone back on.

 What to do after you change your Apple ID or password - Apple Support  *  I suggest doing this before you change your Apple ID or password.

That frees up the address so you can switch it to the other ID.

Apple hasn’t published any guidance for using an address again. Normally, if your e-mail address was associated with an ID in any way, then it can't be reused as an  Apple ID email address for approximately one year. I have also seen posts that stated Apple told them there was a 30 day waiting period before the address could be used again. You can try waiting 30 days to see if that works.

Expect the now-deleted Apple ID and associated Apple email address to never be available again.