Unfortunately, email format validation (similar to HTML email) is somewhat of a black art:<p><a href="http:&#x2F;&#x2F;haacked.com&#x2F;archive&#x2F;2007&#x2F;08&#x2F;21&#x2F;i-knew-how-to-validate-an-email-address-until-i.aspx&#x2F;" rel="nofollow">http:&#x2F;&#x2F;haacked.com&#x2F;archive&#x2F;2007&#x2F;08&#x2F;21&#x2F;i-knew-how-to-validate...</a><p><a href="http:&#x2F;&#x2F;girders.org&#x2F;blog&#x2F;2013&#x2F;01&#x2F;31&#x2F;dont-rfc-validate-email-addresses&#x2F;" rel="nofollow">http:&#x2F;&#x2F;girders.org&#x2F;blog&#x2F;2013&#x2F;01&#x2F;31&#x2F;dont-rfc-validate-email-a...</a><p>Of course one could always just go with RFC822 and this little regex:<p><a href="http:&#x2F;&#x2F;www.ex-parrot.com&#x2F;pdw&#x2F;Mail-RFC822-Address.html" rel="nofollow">http:&#x2F;&#x2F;www.ex-parrot.com&#x2F;pdw&#x2F;Mail-RFC822-Address.html</a>