Mail starting with apostrophe should be invalid

[janbarasek]

Version: v3.1.2

Bug Description

Input Validators::isEmail("'jan@barasek.com") return true, but I think it is not valid address, because it starting with apostrophe.

Expected Behavior

Addresses starting or ending with special characters should be detected as invalid.

I'm not sure how to elegantly implement this into the current regular expression, so I'm starting an issue.

Thanks!

[dg]

but I think it is not valid address

why?

[janbarasek]

Because I've been processing data files with hundreds of thousands of addresses in the last week, and this case looks like an error.

I think the function could contain a second parameter that turns on strict mode, which filters out some special cases that are potentially an error. It also solves cases where the user copies his e-mail from somewhere, for example to a form.