Allow long email addresses per rfc 5321

src/EmailAddress.php

@@ -69,6 +69,7 @@ class EmailAddress extends AbstractValidator
         'useDeepMxCheck'    => false,
         'useDomainCheck'    => true,
         'allow'             => Hostname::ALLOW_DNS,
+        'strict'            => true,
         'hostnameValidator' => null,
     ];
 
@@ -78,6 +79,7 @@ class EmailAddress extends AbstractValidator
      * The following additional option keys are supported:
      * 'hostnameValidator' => A hostname validator, see Zend\Validator\Hostname
      * 'allow'             => Options for the hostname validator, see Zend\Validator\Hostname::ALLOW_*
+     * 'strict'            => Whether to adhere to strictest requirements in the spec
      * 'useMxCheck'        => If MX check should be enabled, boolean
      * 'useDeepMxCheck'    => If a deep MX check should be done, boolean
      *
@@ -499,7 +501,7 @@ public function isValid($value)
             return false;
         }
 
-        if ((strlen($this->localPart) > 64) || (strlen($this->hostname) > 255)) {
+        if ($this->getOption('strict') && (strlen($this->localPart) > 64) || (strlen($this->hostname) > 255)) {
             $length = false;
             $this->error(self::LENGTH_EXCEEDED);
         }
@@ -542,7 +544,13 @@ protected function idnToAscii($email)
     protected function idnToUtf8($email)
     {
         if (extension_loaded('intl')) {
-            return idn_to_utf8($email);
+            // The documentation does not clarify what kind of failure
+            // can happen in idn_to_utf8. One can assume if the source
+            // is not IDN encoded, it would fail, but it usually returns
+            // the source string in those cases.
+            // But not when the source string is long enough.
+            // Thus we default to source string ourselves.
+            return idn_to_utf8($email) ?: $email;
         }
         return $email;
     }

test/EmailAddressTest.php

@@ -293,6 +293,29 @@ public function testComplexLocalValid()
         }
     }
 
+    /**
+     * Ensures that the validator follows expected behavior for valid email addresses with the non-strict option
+     *
+     * @return void
+     */
+    public function testNonStrict()
+    {
+        $validator = new EmailAddress(['strict' => false]);
+        $emailAddresses = [
+            // RFC 5321 does mention a limit of 64 for the username,
+            // but it also states "To the maximum extent possible,
+            // implementation techniques that impose no limits on the
+            // length of these objects should be used.".
+            // http://tools.ietf.org/html/rfc5321#section-4.5.3.1
+            'line length 320' => str_repeat('x', 309).'@domain.com',
+            'line length 321' => str_repeat('x', 310).'@domain.com',
+            'line length 911' => str_repeat('x', 900).'@domain.com',
+        ];
+        foreach ($emailAddresses as $input) {
+            $this->assertTrue($validator->isValid($input));
+        }
+    }
+
    /**
      * Ensures that the validator follows expected behavior for checking MX records
      *