aqs.org/rfcs/rfc2822.html">RFC 2822 and one can come up with a regular expression matching
all valid email addresses as per specification. However, as this
article discusses it is not necessarily practical to implement a 100% compliant email validator. This implementation is a trade-off trying to match most email while ignoring for example emails with double quotes or comments.
Note: This validator required Java 6, because it uses {@code java.lang.IDN} to support internationalized domain names (IDNs).
@author Emmanuel Bernard
@author Hardy Ferentschik