Subscribing to the mailing list without a Google account?

I sent an email to client-dev+subscribe@letsencrypt.org and it responds with a confirmation link, which makes me put in my email and fill in a captcha. I do this, it sends me another email with a confirmation link, which makes me fill in my email and a captcha, then sends me a confirmation email… this repeats seemingly infinitely. Is there some other process to subscribe to the mailing list without a Google account, or must I conform to the will of our corporate overlord and use my gmail address?