[Aethylia]

I'm not sure this is true. In my experience a lot of people actually do think that it's case sensitive. Many times I've heard someone describe the capitals while verbally telling someone their addresss.

However it being insensitive has probably helped a lot of times where people make mistakes in explaining or copying those capitals.

[croes]

Regarding email it doesn't hurt to think they are case sensitive but opposite would be a massive problem

[Gigachad]

As a sender, you should always treat email as case sensitive. As an email host/receiver, you can and probably should chose to be insensitive. But never assume any other host works like that.

Similar to how gmail ignores . in emails but other hosts do not.

[tsimionescu]

> In my experience a lot of people actually do think that it's case sensitive.

I don't think they really do. They may think case matters somehow, and so may be careful to reproduce the exact case that they used before, but I don't think many people would expect [e-mail] and [e-mail] to be too different email accounts.

[ghaff]

In the general population, how many people do you think understand that username (including an email address) probably isn't case sensitive but that password almost certainly is?