Thank you for your post and welcome to our community forums. We're here to help.
I'm very sorry to hear that you're struggling to delete/deactivate an old email address. So that I can assist you further, I'm going to send you a private message in a few moments. Please respond to this when you can and we'll proceed from there with this.
Thank you for getting back to me so promptly via private message so that we could assist you further. I'm glad that we were able to reach a resolution to your concerns.
Please do let us know if there's anything more that we can assist you with.