diff --git a/README.md b/README.md
index 2ed67b2..84616fb 100644
--- a/README.md
+++ b/README.md
@@ -21,8 +21,11 @@ To detect multi-accounts on your website.
 ## Usage
 
 ```php
-$cleaner = new \bkrukowski\TransparentEmail\TransparentEmail();
-$transformedEmail = $cleaner->getPrimaryEmail('John.Doe+alias@gmail.com');
+use \bkrukowski\TransparentEmail\TransparentEmail;
+use \bkrukowski\TransparentEmail\Emails\Email;
+
+$cleaner = new TransparentEmail();
+$transformedEmail = $cleaner->getPrimaryEmail(new Email('John.Doe+alias@gmail.com'));
 ```
 
 ## Yahoo.com
diff --git a/src/Emails/Email.php b/src/Emails/Email.php
new file mode 100644
index 0000000..f94b955
--- /dev/null
+++ b/src/Emails/Email.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace bkrukowski\TransparentEmail\Emails;
+
+class Email implements EmailInterface
+{
+    use EmailTrait;
+
+    public function __construct(string $email, bool $caseSensitive = false)
+    {
+        $this->validateEmail($email);
+        list($this->localPart, $this->domain) = explode('@', $email);
+        if (!$caseSensitive) {
+            $this->localPart = strtolower($this->localPart);
+        }
+        $this->domain = strtolower($this->domain);
+    }
+
+    private function validateEmail(string $email)
+    {
+        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
+            throw new InvalidEmailException("Email '{$email}' is not valid!");
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Emails/EmailInterface.php b/src/Emails/EmailInterface.php
new file mode 100644
index 0000000..28fa4e1
--- /dev/null
+++ b/src/Emails/EmailInterface.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace bkrukowski\TransparentEmail\Emails;
+
+interface EmailInterface
+{
+    public function getLocalPart() : string;
+
+    /**
+     * @return string Domain in lowercase
+     */
+    public function getDomain() : string;
+
+    public function __toString() : string;
+}
\ No newline at end of file
diff --git a/src/Emails/EmailTrait.php b/src/Emails/EmailTrait.php
new file mode 100644
index 0000000..f741832
--- /dev/null
+++ b/src/Emails/EmailTrait.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace bkrukowski\TransparentEmail\Emails;
+
+trait EmailTrait
+{
+    private $localPart;
+
+    private $domain;
+
+    public function getLocalPart() : string
+    {
+        return $this->localPart;
+    }
+
+    public function getDomain() : string
+    {
+        return $this->domain;
+    }
+
+    public function __toString() : string
+    {
+        return $this->localPart . '@' . $this->domain;
+    }
+}
\ No newline at end of file
diff --git a/src/InvalidEmailException.php b/src/Emails/InvalidEmailException.php
similarity index 55%
rename from src/InvalidEmailException.php
rename to src/Emails/InvalidEmailException.php
index fe48abd..43327a8 100644
--- a/src/InvalidEmailException.php
+++ b/src/Emails/InvalidEmailException.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace bkrukowski\TransparentEmail;
+namespace bkrukowski\TransparentEmail\Emails;
 
 class InvalidEmailException extends \Exception
 {
diff --git a/src/Emails/MutableEmail.php b/src/Emails/MutableEmail.php
new file mode 100644
index 0000000..c6cda8e
--- /dev/null
+++ b/src/Emails/MutableEmail.php
@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace bkrukowski\TransparentEmail\Emails;
+
+/**
+ * @internal
+ */
+class MutableEmail implements EmailInterface
+{
+    use EmailTrait;
+
+    public function __construct(EmailInterface $email)
+    {
+        $this->localPart = $email->getLocalPart();
+        $this->domain = $email->getDomain();
+    }
+
+    public function removeFromLocalPart(string $toRemove) : MutableEmail
+    {
+        $this->localPart = str_replace($toRemove, '', $this->localPart);
+
+        return $this;
+    }
+
+    public function removeSuffixAlias(string $delimiter) : MutableEmail
+    {
+        $this->localPart = explode($delimiter, $this->localPart, 2)[0];
+
+        return $this;
+    }
+
+    public function setDomain(string $domain) : MutableEmail
+    {
+        $this->domain = $domain;
+
+        return $this;
+    }
+
+    public function setLocalPart(string $localPart) : MutableEmail
+    {
+        $this->localPart = $localPart;
+
+        return $this;
+    }
+
+    public function lowerCaseLocalPartIf(bool $condition) : MutableEmail
+    {
+        if ($condition) {
+            $this->localPart = strtolower($this->localPart);
+        }
+
+        return $this;
+    }
+}
\ No newline at end of file
diff --git a/src/Services/AppsGoogleCom.php b/src/Services/AppsGoogleCom.php
index ee88ff9..59f34e8 100644
--- a/src/Services/AppsGoogleCom.php
+++ b/src/Services/AppsGoogleCom.php
@@ -4,14 +4,13 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Services;
 
-/**
- * @internal
- */
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
 class AppsGoogleCom extends GmailCom
 {
-    public function isDomainSupported(string $domain) : bool
+    public function isSupported(EmailInterface $email) : bool
     {
-        getmxrr($domain, $mxhosts);
+        getmxrr($email->getDomain(), $mxhosts);
         $regex1 = '#\\.googlemail\\.com$#';
         $regex2 = '#\\.google\\.com$#';
         foreach ($mxhosts as $host) {
diff --git a/src/Services/GmailCom.php b/src/Services/GmailCom.php
index 6e399d3..49cc461 100644
--- a/src/Services/GmailCom.php
+++ b/src/Services/GmailCom.php
@@ -4,28 +4,34 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Services;
 
-/**
- * @internal
- */
+use bkrukowski\TransparentEmail\Emails\MutableEmail;
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
 class GmailCom implements ServiceInterface
 {
-    public function getPrimaryEmail(string $email) : string
+    public function getPrimaryEmail(EmailInterface $email) : EmailInterface
     {
-        list($name, $domain) = explode('@', strtolower($email));
-
-        return explode('+', str_replace('.', '', $name))[0] . '@' . $this->mapDomain($domain);
+        return (new MutableEmail($email))
+            ->removeFromLocalPart('.')
+            ->removeSuffixAlias('+')
+            ->lowerCaseLocalPartIf(true)
+            ->setDomain($this->mapDomain($email->getDomain()));
     }
 
-    public function isDomainSupported(string $domain) : bool
+    public function isSupported(EmailInterface $email) : bool
     {
-        return in_array(strtolower($domain), ['gmail.com', 'googlemail.com']);
+        return in_array($email->getDomain(), ['gmail.com', 'googlemail.com']);
+    }
+
+    protected function getDomainMapping() : array
+    {
+        return [
+            'googlemail.com' => 'gmail.com',
+        ];
     }
 
     private function mapDomain(string $domain) : string
     {
-        $mapping = [
-            'googlemail.com' => 'gmail.com',
-        ];
-        return $mapping[$domain] ?? $domain;
+        return $this->getDomainMapping()[$domain] ?? $domain;
     }
 }
\ No newline at end of file
diff --git a/src/Services/MultiDomain.php b/src/Services/MultiDomain.php
index e882b60..fe33d70 100644
--- a/src/Services/MultiDomain.php
+++ b/src/Services/MultiDomain.php
@@ -4,23 +4,21 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Services;
 
-/**
- * @internal
- */
+use bkrukowski\TransparentEmail\Emails\MutableEmail;
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
 abstract class MultiDomain implements ServiceInterface
 {
-    public function getPrimaryEmail(string $email) : string
+    public function getPrimaryEmail(EmailInterface $email) : EmailInterface
     {
-        if (!$this->isCaseSensitive()) {
-            $email = strtolower($email);
-        }
-
-        return explode('@', $email)[0] . '@' . $this->getPrimaryDomain();
+        return (new MutableEmail($email))
+            ->setDomain($this->getPrimaryDomain())
+            ->lowerCaseLocalPartIf(!$this->isCaseSensitive());
     }
 
-    public function isDomainSupported(string $domain) : bool
+    public function isSupported(EmailInterface $email) : bool
     {
-        return in_array(strtolower($domain), $this->getDomainList());
+        return in_array($email->getDomain(), $this->getDomainList(), true);
     }
 
     /**
diff --git a/src/Services/OutlookCom.php b/src/Services/OutlookCom.php
index c185b9f..60bfdcf 100644
--- a/src/Services/OutlookCom.php
+++ b/src/Services/OutlookCom.php
@@ -4,20 +4,20 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Services;
 
-/**
- * @internal
- */
+use bkrukowski\TransparentEmail\Emails\MutableEmail;
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
 class OutlookCom implements ServiceInterface
 {
-    public function getPrimaryEmail(string $email) : string
+    public function getPrimaryEmail(EmailInterface $email) : EmailInterface
     {
-        list($name, $domain) = explode('@', strtolower($email));
-
-        return explode('+', $name)[0] . '@' . $domain;
+        return (new MutableEmail($email))
+            ->removeSuffixAlias('+')
+            ->lowerCaseLocalPartIf(true);
     }
 
-    public function isDomainSupported(string $domain) : bool
+    public function isSupported(EmailInterface $email) : bool
     {
-        return in_array(strtolower($domain), ['outlook.com', 'hotmail.com']);
+        return in_array($email->getDomain(), ['outlook.com', 'hotmail.com'], true);
     }
 }
\ No newline at end of file
diff --git a/src/Services/ServiceInterface.php b/src/Services/ServiceInterface.php
index 948c06f..5624026 100644
--- a/src/Services/ServiceInterface.php
+++ b/src/Services/ServiceInterface.php
@@ -2,12 +2,11 @@
 
 namespace bkrukowski\TransparentEmail\Services;
 
-/**
- * @internal
- */
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
 interface ServiceInterface
 {
-    public function isDomainSupported(string $domain) : bool;
+    public function isSupported(EmailInterface $email) : bool;
 
-    public function getPrimaryEmail(string $email) : string;
+    public function getPrimaryEmail(EmailInterface $email) : EmailInterface;
 }
\ No newline at end of file
diff --git a/src/Services/TlenPl.php b/src/Services/TlenPl.php
index 1dec5c2..5e91f10 100644
--- a/src/Services/TlenPl.php
+++ b/src/Services/TlenPl.php
@@ -6,7 +6,6 @@ namespace bkrukowski\TransparentEmail\Services;
 
 /**
  * @codeCoverageIgnore
- * @internal
  */
 class TlenPl extends MultiDomain
 {
diff --git a/src/Services/Www33MailCom.php b/src/Services/Www33MailCom.php
index 6750667..996eab2 100644
--- a/src/Services/Www33MailCom.php
+++ b/src/Services/Www33MailCom.php
@@ -4,20 +4,19 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Services;
 
-/**
- * @internal
- */
+use bkrukowski\TransparentEmail\Emails\MutableEmail;
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
 class Www33MailCom implements ServiceInterface
 {
-    public function getPrimaryEmail(string $email) : string
+    public function getPrimaryEmail(EmailInterface $email) : EmailInterface
     {
-        list(, $domain) = explode('@', strtolower($email));
-
-        return preg_replace('/\\.33mail\\.com$/', '', $domain) . '@' . $domain;
+        return (new MutableEmail($email))
+            ->setLocalPart(preg_replace('/\\.33mail\\.com$/', '', $email->getDomain()));
     }
 
-    public function isDomainSupported(string $domain) : bool
+    public function isSupported(EmailInterface $email) : bool
     {
-        return (bool) preg_match('/\\.33mail\\.com$/', strtolower($domain));
+        return (bool) preg_match('/\\.33mail\\.com$/', $email->getDomain());
     }
 }
\ No newline at end of file
diff --git a/src/Services/YahooCom.php b/src/Services/YahooCom.php
index bcfcc25..6ff47ef 100644
--- a/src/Services/YahooCom.php
+++ b/src/Services/YahooCom.php
@@ -4,20 +4,20 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Services;
 
-/**
- * @internal
- */
+use bkrukowski\TransparentEmail\Emails\MutableEmail;
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
 class YahooCom implements ServiceInterface
 {
-    public function getPrimaryEmail(string $email) : string
+    public function getPrimaryEmail(EmailInterface $email) : EmailInterface
     {
-        list($name, $domain) = explode('@', strtolower($email));
-
-        return explode('-', $name, 2)[0] . '@' . $domain;
+        return (new MutableEmail($email))
+            ->removeSuffixAlias('-')
+            ->lowerCaseLocalPartIf(true);
     }
 
-    public function isDomainSupported(string $domain) : bool
+    public function isSupported(EmailInterface $email) : bool
     {
-        return strtolower($domain) === 'yahoo.com';
+        return $email->getDomain() === 'yahoo.com';
     }
 }
\ No newline at end of file
diff --git a/src/TransparentEmail.php b/src/TransparentEmail.php
index 4172243..5758b1d 100644
--- a/src/TransparentEmail.php
+++ b/src/TransparentEmail.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail;
 
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
 use bkrukowski\TransparentEmail\Services\ServiceInterface;
 
 class TransparentEmail
@@ -13,48 +14,19 @@ class TransparentEmail
      */
     private $services;
 
-    /**
-     * @var bool
-     */
-    private $caseSensitive;
-
-    public function __construct(ServiceCollectorInterface $services = null, bool $caseSensitive = false)
+    public function __construct(ServiceCollectorInterface $services = null)
     {
         $this->services = $services ?: new DefaultServiceCollector();
-        $this->caseSensitive = $caseSensitive;
     }
 
-    /**
-     * @param string $email
-     * @return string
-     * @throws InvalidEmailException
-     */
-    public function getPrimaryEmail(string $email)
+    public function getPrimaryEmail(EmailInterface $email) : EmailInterface
     {
-        $this->validateEmailAddress($email);
-        if (!$this->caseSensitive) {
-            $email = strtolower($email);
-        }
-        $domain = strtolower(explode('@', $email)[1]);
-        $result = $email;
-
         foreach ($this->services as $service) {
-            if ($service->isDomainSupported($domain)) {
-                $result = $service->getPrimaryEmail($result);
+            if ($service->isSupported($email)) {
+                return $service->getPrimaryEmail($email);
             }
         }
 
-        return $result;
-    }
-
-    /**
-     * @param string $email
-     * @throws InvalidEmailException
-     */
-    private function validateEmailAddress(string $email)
-    {
-        if (filter_var($email, FILTER_VALIDATE_EMAIL) === false) {
-            throw new InvalidEmailException("Invalid email '{$email}'!");
-        }
+        return $email;
     }
 }
\ No newline at end of file
diff --git a/tests/Emails/EmailTest.php b/tests/Emails/EmailTest.php
new file mode 100644
index 0000000..c5b1fc0
--- /dev/null
+++ b/tests/Emails/EmailTest.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace bkrukowski\TransparentEmail\Tests\Emails;
+
+use bkrukowski\TransparentEmail\Emails\Email;
+use bkrukowski\TransparentEmail\Emails\InvalidEmailException;
+
+class EmailTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @dataProvider providerConstructor
+     *
+     * @param string $email
+     * @param bool $expectedException
+     * @param string $localPart
+     * @param string $domain
+     * @param bool $caseSensitive
+     */
+    public function testConstructor(
+        string $email,
+        bool $expectedException,
+        string $localPart = '',
+        string $domain = '',
+        bool $caseSensitive = false
+    ) {
+        if ($expectedException) {
+            $this->expectException(InvalidEmailException::class);
+        }
+        $object = new Email($email, $caseSensitive);
+        $this->assertSame($localPart, $object->getLocalPart());
+        $this->assertSame($domain, $object->getDomain());
+    }
+
+    public function providerConstructor()
+    {
+        return [
+            ['john doe@example.com', true],
+            ['.johndoe@example.com', true],
+            ['Jane.Doe@Example.COM', false, 'Jane.Doe', 'example.com', true],
+            ['Jane.Doe@Example.COM', false, 'jane.doe', 'example.com'],
+        ];
+    }
+}
\ No newline at end of file
diff --git a/tests/Emails/MutableEmailTest.php b/tests/Emails/MutableEmailTest.php
new file mode 100644
index 0000000..05f973d
--- /dev/null
+++ b/tests/Emails/MutableEmailTest.php
@@ -0,0 +1,126 @@
+<?php
+
+namespace bkrukowski\TransparentEmail\Tests\Emails;
+
+use bkrukowski\TransparentEmail\Emails\MutableEmail;
+use bkrukowski\TransparentEmail\Emails\Email;
+use bkrukowski\TransparentEmail\Emails\EmailInterface;
+
+class MutableEmailTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @dataProvider providerRemoveFromLocalPart
+     *
+     * @param EmailInterface $email
+     * @param string $toRemove
+     */
+    public function testRemoveFromLocalPart(EmailInterface $email, string $toRemove)
+    {
+        $editable = new MutableEmail($email);
+        $this->assertSame($editable, $editable->removeFromLocalPart($toRemove));
+        $this->assertNotContains((string) $editable, $toRemove);
+        $this->assertSame($email->getDomain(), $editable->getDomain());
+    }
+
+    public function providerRemoveFromLocalPart()
+    {
+        return [
+            [new Email('jane.doe.1990@gmail.com'), '.'],
+            [new Email('janedoe1990@gmail.com'), '.'],
+        ];
+    }
+
+    /**
+     * @dataProvider providerRemoveSuffixAlias
+     *
+     * @param EmailInterface $email
+     * @param string $delimiter
+     * @param string $expected
+     */
+    public function testRemoveSuffixAlias(EmailInterface $email, string $delimiter, string $expected)
+    {
+        $editable = new MutableEmail($email);
+        $this->assertSame($editable, $editable->removeSuffixAlias($delimiter));
+        $this->assertEquals($expected, $editable);
+        $this->assertSame($email->getDomain(), $editable->getDomain());
+    }
+
+    public function providerRemoveSuffixAlias()
+    {
+        return [
+            [new Email('John.Doe+alias@gmail.com', true), '+', 'John.Doe@gmail.com'],
+            [new Email('JohnDoe-alias@gmail.com'), '-', 'johndoe@gmail.com'],
+            [new Email('JohnDoe@gmail.com'), '-', 'johndoe@gmail.com'],
+        ];
+    }
+
+    /**
+     * @dataProvider providerSetDomain
+     *
+     * @param EmailInterface $email
+     * @param string $domain
+     */
+    public function testSetDomain(EmailInterface $email, string $domain)
+    {
+        $editable = new MutableEmail($email);
+        $this->assertSame($editable, $editable->setDomain($domain));
+        $this->assertSame($domain, $editable->getDomain());
+        $this->assertSame($email->getLocalPart(), $editable->getLocalPart());
+    }
+
+    public function providerSetDomain()
+    {
+        return [
+            [new Email('jane.doe@foo.bar'), 'gmail.com'],
+            [new Email('jane.doe@foo.bar'), 'foo.bar'],
+            [new Email('jane.doe@gmail.com'), 'foo.bar'],
+        ];
+    }
+
+    /**
+     * @dataProvider providerSetLocalPart
+     *
+     * @param EmailInterface $email
+     * @param string $localPart
+     */
+    public function testLocalPart(EmailInterface $email, string $localPart)
+    {
+        $editable = new MutableEmail($email);
+        $this->assertSame($editable, $editable->setLocalPart($localPart));
+        $this->assertSame($localPart, $editable->getLocalPart());
+        $this->assertSame($email->getDomain(), $editable->getDomain());
+    }
+
+    public function providerSetLocalPart()
+    {
+        return [
+            [new Email('jane.doe@foo.bar'), 'jane'],
+            [new Email('jane.doe@foo.bar'), 'john'],
+            [new Email('jane.doe@gmail.com'), 'jane.doe'],
+        ];
+    }
+
+    /**
+     * @dataProvider providerLowerCaseLocalPartIf
+     *
+     * @param EmailInterface $email
+     * @param bool $condition
+     * @param bool $expected
+     */
+    public function testLowerCaseLocalPartIf(EmailInterface $email, bool $condition, bool $expected)
+    {
+        $editable = new MutableEmail($email);
+        $this->assertSame($editable, $editable->lowerCaseLocalPartIf($condition));
+        $this->assertSame($expected, strtolower($editable->getLocalPart()) === $editable->getLocalPart());
+        $this->assertSame($email->getDomain(), $editable->getDomain());
+    }
+
+    public function providerLowerCaseLocalPartIf()
+    {
+        return [
+            [new Email('john.doe@example.com', true), false, true],
+            [new Email('John.doe@example.com', true), false, false],
+            [new Email('John.doe@example.com', true), true, true],
+        ];
+    }
+}
\ No newline at end of file
diff --git a/tests/Services/AppsGoogleComTest.php b/tests/Services/AppsGoogleComTest.php
index ee16fbd..bcb0ba0 100644
--- a/tests/Services/AppsGoogleComTest.php
+++ b/tests/Services/AppsGoogleComTest.php
@@ -4,26 +4,29 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Tests\Services;
 
+use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\AppsGoogleCom;
 
 class AppsGoogleComTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @dataProvider providerIsDomainSupported
+     * @dataProvider providerIsSupported
      *
      * @param string $domain
      * @param bool $result
      */
-    public function testIsDomainSupported(string $domain, bool $result)
+    public function testIsSupported(string $domain, bool $result)
     {
-        $this->assertSame($result, (new AppsGoogleCom())->isDomainSupported($domain));
+        $this->assertSame($result, (new AppsGoogleCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsDomainSupported()
+    public function providerIsSupported()
     {
         return [
             ['example.com', false],
+            ['EXAMPLE.COM', false],
             ['krukowski.me', true],
+            ['KRUKOWSKI.ME', true],
         ];
     }
 }
\ No newline at end of file
diff --git a/tests/Services/GmailComTest.php b/tests/Services/GmailComTest.php
index f371b75..3eac764 100644
--- a/tests/Services/GmailComTest.php
+++ b/tests/Services/GmailComTest.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Tests\Services;
 
+use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\GmailCom;
 
 class GmailComTest extends \PHPUnit_Framework_TestCase
@@ -16,7 +17,7 @@ class GmailComTest extends \PHPUnit_Framework_TestCase
      */
     public function testGetPrimaryEmail(string $inputEmail, string $outputEmail)
     {
-        $this->assertSame($outputEmail, (new GmailCom())->getPrimaryEmail($inputEmail));
+        $this->assertEquals($outputEmail, (new GmailCom())->getPrimaryEmail(new Email($inputEmail)));
     }
 
     public function providerGetPrimaryEmail()
@@ -31,24 +32,26 @@ class GmailComTest extends \PHPUnit_Framework_TestCase
     }
 
     /**
-     * @dataProvider providerIsDomainSupported
+     * @dataProvider providerIsSupported
      *
      * @param string $domain
      * @param bool $result
      */
-    public function testIsDomainSupported(string $domain, bool $result)
+    public function testIsSupported(string $domain, bool $result)
     {
-        $this->assertSame($result, (new GmailCom())->isDomainSupported($domain));
+        $this->assertSame($result, (new GmailCom())->isSupported(new Email('Jane.Doe@' . $domain)));
     }
 
-    public function providerIsDomainSupported()
+    public function providerIsSupported()
     {
         return [
             ['gmail.com', true],
             ['gmail.COM', true],
             ['google.com', false],
-            ['gmailcom', false],
-            ['g.mail.com', false]
+            ['test.gmailcom', false],
+            ['g.mail.com', false],
+            ['googlemail.com', true],
+            ['GoogleMail.Com', true],
         ];
     }
 }
\ No newline at end of file
diff --git a/tests/Services/MultiDomainTest.php b/tests/Services/MultiDomainTest.php
index 9ff7911..60f843e 100644
--- a/tests/Services/MultiDomainTest.php
+++ b/tests/Services/MultiDomainTest.php
@@ -4,23 +4,24 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Tests\Services;
 
+use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\MultiDomain;
 
 class MultiDomainTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @dataProvider providerIsDomainSupported
+     * @dataProvider providerIsSupported
      *
      * @param MultiDomain $mock
      * @param string $domain
      * @param bool $expected
      */
-    public function testIsDomainSupported(MultiDomain $mock, string $domain, bool $expected)
+    public function testIsSupported(MultiDomain $mock, string $domain, bool $expected)
     {
-        $this->assertSame($expected, $mock->isDomainSupported($domain));
+        $this->assertSame($expected, $mock->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsDomainSupported()
+    public function providerIsSupported()
     {
         return [
             [$this->getMultiDomainMock('foo.bar', ['foo.bar']), 'gmail.com', false],
@@ -37,9 +38,8 @@ class MultiDomainTest extends \PHPUnit_Framework_TestCase
      * @param string $email
      * @param string $expectedEmail
      */
-    public function testGetPrimaryDomain(MultiDomain $mock, string $email, string $expectedEmail)
-    {
-        $this->assertSame($expectedEmail, $mock->getPrimaryEmail($email));
+    public function testGetPrimaryDomain(MultiDomain $mock, string $email, string $expectedEmail) {
+        $this->assertEquals($expectedEmail, $mock->getPrimaryEmail(new Email($email, true)));
     }
 
     public function providerGetPrimaryDomain()
@@ -47,6 +47,7 @@ class MultiDomainTest extends \PHPUnit_Framework_TestCase
         return [
             [$this->getMultiDomainMock('foo.bar', ['foo.bar', 'foo.bar2']), 'name@foo.bar', 'name@foo.bar'],
             [$this->getMultiDomainMock('foo.bar', ['foo.bar', 'foo.bar2'], true), 'Name@foo.bar', 'Name@foo.bar'],
+            [$this->getMultiDomainMock('foo.bar', ['foo.bar', 'foo.bar2'], true), 'Name@FOO.bar', 'Name@foo.bar'],
             [$this->getMultiDomainMock('foo.bar', ['foo.bar', 'foo.bar2']), 'name@foo.bar2', 'name@foo.bar'],
         ];
     }
diff --git a/tests/Services/OutlookComTest.php b/tests/Services/OutlookComTest.php
index f53a4cc..4849971 100644
--- a/tests/Services/OutlookComTest.php
+++ b/tests/Services/OutlookComTest.php
@@ -4,22 +4,23 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Tests\Services;
 
+use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\OutlookCom;
 
 class OutlookComTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @dataProvider providerIsDomainSupported
+     * @dataProvider providerIsSupported
      *
      * @param string $domain
      * @param bool $result
      */
-    public function testIsDomainSupported(string $domain, bool $result)
+    public function testIsSupported(string $domain, bool $result)
     {
-        $this->assertSame($result, (new OutlookCom())->isDomainSupported($domain));
+        $this->assertSame($result, (new OutlookCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsDomainSupported()
+    public function providerIsSupported()
     {
         return [
             ['outlook.com', true],
@@ -39,7 +40,7 @@ class OutlookComTest extends \PHPUnit_Framework_TestCase
      */
     public function testGetPrimaryEmail(string $inputEmail, string $expectedEmail)
     {
-        $this->assertSame($expectedEmail, (new OutlookCom())->getPrimaryEmail($inputEmail));
+        $this->assertEquals($expectedEmail, (new OutlookCom())->getPrimaryEmail(new Email($inputEmail, true)));
     }
 
     public function providerGetPrimaryEmail()
diff --git a/tests/Services/Www33MailComTest.php b/tests/Services/Www33MailComTest.php
index ddd7978..e6a5ef4 100644
--- a/tests/Services/Www33MailComTest.php
+++ b/tests/Services/Www33MailComTest.php
@@ -4,22 +4,23 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Tests\Services;
 
+use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\Www33MailCom;
 
 class Www33MailComTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @dataProvider providerIsDomainSupported
+     * @dataProvider providerIsSupported
      *
      * @param string $domain
      * @param bool $isSupported
      */
-    public function testIsDomainSupported(string $domain, bool $isSupported)
+    public function testIsSupported(string $domain, bool $isSupported)
     {
-        $this->assertSame($isSupported, (new Www33MailCom())->isDomainSupported($domain));
+        $this->assertSame($isSupported, (new Www33MailCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsDomainSupported()
+    public function providerIsSupported()
     {
         return [
             ['foo.33mail.com', true],
@@ -38,7 +39,7 @@ class Www33MailComTest extends \PHPUnit_Framework_TestCase
      */
     public function testGetPrimaryEmail(string $inputEmail, string $expectedEmail)
     {
-        $this->assertSame($expectedEmail, (new Www33MailCom())->getPrimaryEmail($inputEmail));
+        $this->assertEquals($expectedEmail, (new Www33MailCom())->getPrimaryEmail(new Email($inputEmail, true)));
     }
 
     public function providerGetPrimaryEmail()
diff --git a/tests/Services/YahooComTest.php b/tests/Services/YahooComTest.php
index ec2d47a..7ce476c 100644
--- a/tests/Services/YahooComTest.php
+++ b/tests/Services/YahooComTest.php
@@ -4,22 +4,23 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Tests\Services;
 
+use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\Services\YahooCom;
 
 class YahooComTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @dataProvider providerIsDomainSupported
+     * @dataProvider providerIsSupported
      *
      * @param string $domain
      * @param bool $result
      */
     public function testIsDomainSupported(string $domain, bool $result)
     {
-        $this->assertSame($result, (new YahooCom())->isDomainSupported($domain));
+        $this->assertSame($result, (new YahooCom())->isSupported(new Email('Jane.Doe@' . $domain, true)));
     }
 
-    public function providerIsDomainSupported()
+    public function providerIsSupported()
     {
         return [
             ['yahoo.com', true],
@@ -40,7 +41,7 @@ class YahooComTest extends \PHPUnit_Framework_TestCase
      */
     public function testGetPrimaryEmail(string $inputEmail, string $expectedEmail)
     {
-        $this->assertSame($expectedEmail, (new YahooCom())->getPrimaryEmail($inputEmail));
+        $this->assertEquals($expectedEmail, (new YahooCom())->getPrimaryEmail(new Email($inputEmail, true)));
     }
 
     public function providerGetPrimaryEmail()
diff --git a/tests/TransparentEmailTest.php b/tests/TransparentEmailTest.php
index 907c765..cd34838 100644
--- a/tests/TransparentEmailTest.php
+++ b/tests/TransparentEmailTest.php
@@ -4,46 +4,29 @@ declare(strict_types=1);
 
 namespace bkrukowski\TransparentEmail\Tests;
 
+use bkrukowski\TransparentEmail\Emails\Email;
 use bkrukowski\TransparentEmail\ServiceCollector;
 use bkrukowski\TransparentEmail\ServiceCollectorInterface;
 use bkrukowski\TransparentEmail\Services\TlenPl;
 use bkrukowski\TransparentEmail\TransparentEmail;
-use bkrukowski\TransparentEmail\InvalidEmailException;
 
 class TransparentEmailTest extends \PHPUnit_Framework_TestCase
 {
-    /**
-     * @dataProvider providerValidator
-     *
-     * @param string $email
-     * @param bool $validEmail
-     */
-    public function testValidator(string $email, bool $validEmail)
-    {
-        if (!$validEmail) {
-            $this->expectException(InvalidEmailException::class);
-        }
-        (new TransparentEmail())->getPrimaryEmail($email);
-    }
-
-    public function providerValidator()
-    {
-        return [
-            ['john.doe@gmail.comm', true],
-            ['john doe@gmail.com', false],
-        ];
-    }
-
     /**
      * @dataProvider providerGetPrimaryEmail
      *
      * @param TransparentEmail $transparentEmail
      * @param string $email
      * @param string $expectedEmail
+     * @param bool $caseSensitive
      */
-    public function testGetPrimaryEmail(TransparentEmail $transparentEmail, string $email, string $expectedEmail)
-    {
-        $this->assertSame($expectedEmail, $transparentEmail->getPrimaryEmail($email));
+    public function testGetPrimaryEmail(
+        TransparentEmail $transparentEmail,
+        string $email,
+        string $expectedEmail,
+        bool $caseSensitive = false
+    ) {
+        $this->assertEquals($expectedEmail, $transparentEmail->getPrimaryEmail(new Email($email, $caseSensitive)));
     }
 
     public function providerGetPrimaryEmail()
@@ -59,8 +42,8 @@ class TransparentEmailTest extends \PHPUnit_Framework_TestCase
             ],
             [new TransparentEmail(), 'john.doe+alias@gmail.com', 'johndoe@gmail.com'],
             [new TransparentEmail($emptyServiceCollector), 'John.Doe@example.com', 'john.doe@example.com'],
-            [new TransparentEmail($emptyServiceCollector, true), 'John.Doe@example.com', 'John.Doe@example.com'],
-            [new TransparentEmail(null, true), 'John.Doe@gmail.com', 'johndoe@gmail.com'],
+            [new TransparentEmail($emptyServiceCollector), 'John.Doe@example.com', 'John.Doe@example.com', true],
+            [new TransparentEmail(), 'John.Doe@gmail.com', 'johndoe@gmail.com', true],
             [new TransparentEmail(), 'Jane.Doe+receipts@hotmail.com', 'jane.doe@hotmail.com'],
             [new TransparentEmail(), 'Jane.Doe-receipts@yahoo.com', 'jane.doe@yahoo.com'],
         ];