Re: Regex for email validation

tedd wrote: > >>No, they can't. There are no 8-bit characters allowed in an >>email-address. Check out RFC2821. > > You can throw all the facts and documentation you want at me, but the > left side of the @ has always been open to anything you want. Except anything 8-bit, yes. Seriously, read RFC2821 and maybe -2822 > The right side of the @ has had to deal with 7-bit limitation (the > DNS problem). But, considering the work that the IDNS has done, (circa > 2000) we can use Unicode characters on both sides of the @. No, you cannot. Certainly not on the left side, and only on the right side if you assume visual representation = email-address. Why don't you send me an email at this address: à@jessen.ch (that's an a with accent grave like in your domain further down). > However, the software (browsers and email apps) may/may-not be able to > deal with it, as shown by my recent example of: > >> > tedd@à.com >>> >>> is a legal and working email address. >> >>If that reads "tedd(at)<space>.com", it might be valid on your system, >>but not in public. > > The email address is perfectly valid, and works, > but our definition of "public" is apparently > different. Sorry, I didn't see the a with the accent grave. Still, try using that address in Thunderbird, and you'll see that it doesn't work. The correct email-address (which is what we're talking about) for 'tedd@à.com' is tedd@xn--0ca.com, which an email-system like sendmail/exim/postfix/etc will understand (whereas it will choke on 'tedd@à.com'. > So, regardless of the documentation, which may be outdated, I know > that Unicode characters can be used in IDNS and thus on both sides of > the @, You're wrong - IDNs only apply to the right side of the @. (check out what the 'D' means). Go on, send me that email to 'à@jessen.ch' ... for what it's worth, I can't even define an account like that, so my mailserver might well reject it. /Per Jessen, Zürich