Posting via e-mail in feature - E-mail address is case sensitive
Not actually a bug – mail addresses (but not domains) are case sensitive, per Wikipedia:
So I guess while its not technically a bug, it can be problematic.
I brought this up because a new user on our forum was having trouble signing in after they were approved - and now I see they just tried to sign up again with the other case as a different user name.
It is due to the Robustness principle Otherwise know as Postel’s law that it works when you do that. It spread from TCP to SMTP.
From the writeup:
“TCP implementations should follow a general principle of robustness: be conservative in what you do, be liberal in what you accept from others.”
Personally, I think people should have to tick a very special site setting if they don’t want
firstname.lastname@example.org to be treated exactly the same as
I am definitely coming around to this way of thinking.
According to your link
The domain part is not case-sensitive, but local-parts may be.
email@example.com is strictly equivalent to
bob@EXAMPLE.COM but may be different from
BOB@example.com. If you really wanted case-sensitive emails you’d have to parse out the case-insensitive domain portion and compare it separately from the local parts.
According to a comment in this StackOverflow answer (emphasis mine):
‘In short, you are safe to treat email addresses as case-insensitive.’ I’d phrase it stronger: “you’re unsafe to treat email-addresses as case-sensitive manner” Especially when checking for duplicates in user-databases, etc.
Several email systems that are case-insensitive and that would cause problems if they were treated case-sensitively:
This problem is fixed. Email is not case sensitive anymore!