validar email

[jgarcigo]

Código:

function validaMail (emailStr) {

var emailPat=/^(.+)@(.+)$/
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
var validChars="\[^\\s" + specialChars + "\]"
var firstChars=validChars
var quotedUser="(\"[^\"]*\")"
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
var atom="(" + firstChars + validChars + "*" + ")"
var word="(" + atom + "|" + quotedUser + ")"
var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")
var matchArray=emailStr.match(emailPat)

if (matchArray==null) {
   //alert("Ingrese un EMail Valido")
   return false;
}

var user=matchArray[1]
var domain=matchArray[2]

if (user.match(userPat)==null) {
    //alert("Su EMail no es Valido.")
    return false
}
var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) { 
	  for (var i=1;i<=4;i++) {
	    if (IPArray[i]>255) {
	        //alert("Su EMail sobrepasa el largo permitido")
		return false
	    }
    }
    return true
}

var domainArray=domain.match(domainPat)
if (domainArray==null) {
	//alert("Formato de Mail no Valido.")
    return false
}

var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length
if (domArr[domArr.length-1].length<2 || 
    domArr[domArr.length-1].length>3) {
   //alert("Formato de mail no Valido")
   return false
}

if (domArr[domArr.length-1].length >= 2 && len < 2) {
   var errStr="Formato de Mail no Valido"
   //alert(errStr)
   return false
}
return true;
}

es un poco extensa pero espero te sirva