Help with email regular expression

I have one, but is it any good?

[twist]

Someone posted this on a message board and some people responded that it was good and others said it might have problems. So I thought I would come to the experts here and get a second opinion.

!eregi( "^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email ) )

Any thoughts?

[ironik]

Looks fine, I'd probably change the 3 to a 6 though to allow for [e-mail] addresses, although most of the domain qualifiers (I think that's what they call them) are either 2 or 3 letters (.com, .net, .co.uk).