Hello, I'm an end user like you. I found this regarding this problem. by any chance do you have a comcast email address?
"If the customer didn't receive the verification email, follow the steps below. The following steps apply to both 2-step verification (2SV) and password reset emails. If the customer doesn’t receive their verification or password reset email, ask them to check the following: Spam folder Promotions folder Junk or Trash if their email filters junk mail directly to the trash Ask if they recently deleted their Nest account or have received an email from Nest that asks to confirm their account's deletion. Note: If they deleted their Nest account, they can’t receive an email from Nest and can’t use that email to create a new Nest account for 24 to 48 hours. Have them try the following: If their mail service uses one, add @Nest.com to their allowlist. The steps on how to do this step vary based on the customer's Internet Service Provider (ISP). If you can't find the steps on how to do this with a simple Google search, then refer the customer to their ISP for help with the process. Some email domains may have an anti-spam feature that could block legitimate emails from Nest inadvertently. If the customer adds # to their allowlist, the customer should receive the verification email. Known domains which block Nest emails at the server level: @btinternet.com and @comcast.com. If the customer still can't receive emails after they add # to their allowlist, advise them to directly contact their ISP or email provider. "
