Valid_email rule not accepting Scandinavian characters

[eluser]Unknown[/eluser]
I have an irritating problem with the valid_email rule while doing form validation: It does not accept Scandinavian characters like æ, ä, ø, ö and å, returns FALSE if one of these characters occur.
Why is this and is there a way to fix this problem?

[eluser]smilie[/eluser]
Afaik, those characters are not permitted in an e-mail address...

See http://en.wikipedia.org/wiki/Email_address#Syntax

Cheers,
Smilie

[eluser]Unknown[/eluser]
Oh, i assumed it was permitted as æ, ø and å is permitted in .no-domains.
Well, you learn something new every day!
Thanks for answering!