Posting via e-mail in feature - E-mail address is case sensitive

[mcwumbly (Dave McClure)]

There are some other places where email case sensitivity has caused issues.

See also:

Create account email address check should be case-insensitive

to reproduce: sign up as joe@example.com sign up on same forum as JOE@EXAMPLE.COM expected: “sorry, that email has already been taken” actual: new account is created

https://meta.discourse.org/t/only-lower-case-emails-allowed-in-validation-form/2808