[irrational]

>If you created your account as [e-mail], you can only log in by using that email address.

I don't think that's quite right if I'm understanding what you are saying. I've logged into my gmail account using both [e-mail] and [e-mail]. Both work and both take me to the same account.

[snowwrestler]

Based on my own limited testing, it seems like you can remove dots but not add them during login.

So if you created your account as [e-mail], you can also log into Google with username [e-mail].

But if you created your account as [e-mail], you can't log in with [e-mail].

[babblingdweeb]

Correct! I forgot, there was a little nuance there. Thanks for posting that.