Email verification not working

BLUF: My domain registration has been cancelled because I haven't been able to verify my email address, but when I click the "resend verification" link, no verification email is sent.

Long version:

I recently changed the email address on my domain registration.  I never received the verification email, but I started getting emails warning me that my registration would be cancelled by ICANN if I didn't verify my new email address.  I would click the "resend verification" link, but would never receive a verification email.  I wasted a lot of time troubleshooting the wrong end of things: checking SPAM fillets and mail account configuration etc.  Yesterday, after my registration was cancelled by ICANN, I finally realized the true cause: I had entered the email address incorrectly and the verification emails were going to a non-existent address.  I edited the contact info on the registration to correct the address, and received an email at the new address notifying me of the change, but still no verification email.  I clicked the "resend verification" link multiple times over the course of a day, but never received a verification email.

I have tried contacting both email and phone support, but have received no response other than an automatic email reply acknowledging receipt of my support request.

Just now, I tried changing the email address on the registration back to the original address, which I know works properly.  This time, I received notification emails about the change at both email addresses, but still no verification email.  Nothing in spam folder, either.

I know that I'm able to receive emails from Dyn at these addresses because I'm receiving the change notification emails, but clicking the "resend verification" link still isn't working.