Otto,
some more useful informations You can find here :
( a very good description about the Email-structure )
( A German Website )
http://aktuell.de.selfhtml.org/artikel/ ... /index.htm
Regards
Uwe 
Possible useful resource for those who wish to do validation using regular expression - http://www.regular-expressions.info/email.html
// The example extracts an eMail address from a text string.
// The search is case insensitive although the RegEx defines
// character classes only with upper case letters.
PROCEDURE Main
LOCAL cRegEx := "[A-Z0-9._%-]+@[A-Z0-9.-]+\.[A-Z]{2,4}"
LOCAL cText := "Send your request to <!-- e --><a href="mailto:info@xharbour.com">info@xharbour.com</a><!-- e --> " + ;
"for more information"
LOCAL cEmail, nStart, nLen
cEmail := HB_AtX( cRegEx, cText, .F., @nStart, @nLen )
? cEmail // result: <!-- e --><a href="mailto:info@xharbour.com">info@xharbour.com</a><!-- e -->
? nStart // result: 22
? nLen // result: 17
RETURN