Authentication: Adding a sign-in URL to "text/plain" emails?

[Hideyoshi Moriya]

Hi Firebase team,

Product/Feature:

Firebase Authentication Email Link

https://firebase.google.com/docs/auth/web/email-link-auth

Question/Feedback:

Is it possible to add a sign-in URL to "text/plain" emails?

Details:

I confirmed a Content-Type of a sign-in email sent from Firebase is "multipart/alternative".

However, our users cannot sign-in via URL when they don't allow rendering HTML because a "text/plain" part doesn't have a sign-in URL (Please see the Example below).

Could you please add a sign-in URL to a "text/plain" part of emails as well as a "text/html" part?

Example: 

Hello,

We received a request to sign in to {APP_NAME} using this email address. If  

you want to sign in with your {USER_EMAIL_ADDRESS} account, click this link:

Sign in to {APP_NAME}

{EMAIL LINK URL SHOULD BE ADDED HERE}

If you did not request this link, you can safely ignore this email.

Thanks!

Hideyoshi