If you haven't already tried it, I did. This seems to work:

- Created email #1 at https://www.guerrillamail.com

- Created test Twitter account using email #1, including receiving email confirmation request

- Created email #2 at https://temp-mail.org/en/

- Without confirming email #1, changed test Twitter account email to email #2

- Received email confirmation request at email #2

- And to be nice, deactivated test Twitter account :)

Good luck!

This ended up working. Thanks so much for the suggestion!

LOL, I was curious if it would work myself, so I tried it and posted the results. It worked for me, too :)

What email provider were you using at first on your account?

GMail. Only thing I can think is that at some point I may have opted out of all emails from Twitter, and somehow this got swept up in that block.