diff --git a/composer.json b/composer.json
index 74ff3fa..afcba2c 100644
--- a/composer.json
+++ b/composer.json
@@ -10,8 +10,8 @@
     ],
     "require": {
         "php": "~8.1.0",
-        "ericmartel/codeception-email": "^1.0",
-        "guzzlehttp/guzzle": "^6.1 || ^7.0"
+        "guzzlehttp/guzzle": "^6.1 || ^7.0",
+        "codeception/codeception": "^5.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
new file mode 100644
index 0000000..4b23813
--- /dev/null
+++ b/phpstan-baseline.neon
@@ -0,0 +1,51 @@
+parameters:
+	ignoreErrors:
+		-
+			message: "#^Access to an undefined property object\\:\\:\\$Body\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Access to an undefined property object\\:\\:\\$Content\\.$#"
+			count: 11
+			path: src/MailHog.php
+
+		-
+			message: "#^Access to an undefined property object\\:\\:\\$MIME\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Cannot access property \\$ID on object\\|null\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Method Codeception\\\\Module\\\\MailHog\\:\\:getFullEmail\\(\\) should return object but returns mixed\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Parameter \\#1 \\$inbox of method Codeception\\\\Module\\\\MailHog\\:\\:sortEmails\\(\\) expects array\\<object\\>, mixed given\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Parameter \\#1 \\$string of function mb_decode_mimeheader expects string, string\\|null given\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Parameter \\#2 \\.\\.\\.\\$arrays of function array_merge expects array, array\\|string given\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Property Codeception\\\\Module\\\\MailHog\\:\\:\\$fetchedEmails \\(array\\<object\\>\\) does not accept mixed\\.$#"
+			count: 1
+			path: src/MailHog.php
+
+		-
+			message: "#^Variable \\$response might not be defined\\.$#"
+			count: 1
+			path: src/MailHog.php
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..ec413c4
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,8 @@
+includes:
+  - phpstan-baseline.neon
+parameters:
+  level: max
+  phpVersion: 80100
+  reportUnmatchedIgnoredErrors: true
+  paths:
+    - src
diff --git a/src/MailHog.php b/src/MailHog.php
index 0d6f28b..5e18b62 100644
--- a/src/MailHog.php
+++ b/src/MailHog.php
@@ -12,6 +12,7 @@
 
 use Codeception\Module;
 use Codeception\TestInterface;
+use Exception;
 
 class MailHog extends Module
 {
@@ -27,46 +28,46 @@ class MailHog extends Module
     /**
      * Raw email header data converted to JSON
      *
-     * @var array
+     * @var array<object>
      */
     protected $fetchedEmails;
 
     /**
      * Currently selected set of email headers to work with
      *
-     * @var array
+     * @var array<object>
      */
     protected $currentInbox;
 
     /**
      * Starts as the same data as the current inbox, but items are removed as they're used
      *
-     * @var array
+     * @var array<object>
      */
     protected $unreadInbox;
 
     /**
      * Contains the currently open email on which test operations are conducted
      *
-     * @var mixed
+     * @var object
      */
     protected $openedEmail;
 
     /**
      * Codeception exposed variables
      *
-     * @var array
+     * @var array<string>
      */
     protected array $config = ['url', 'port', 'guzzleRequestOptions', 'deleteEmailsAfterScenario', 'timeout'];
 
     /**
      * Codeception required variables
      *
-     * @var array
+     * @var array<string>
      */
     protected array $requiredFields = ['url', 'port'];
 
-    public function _initialize()
+    public function _initialize(): void
     {
         $url = trim($this->config['url'], '/') . ':' . $this->config['port'];
 
@@ -83,7 +84,7 @@ public function _initialize()
     /**
      * Method executed after each scenario
      */
-    public function _after(TestInterface $test)
+    public function _after(TestInterface $test): void
     {
         if (isset($this->config['deleteEmailsAfterScenario']) && $this->config['deleteEmailsAfterScenario']) {
             $this->deleteAllEmails();
@@ -95,7 +96,7 @@ public function _after(TestInterface $test)
      *
      * Accessible from tests, deletes all emails
      */
-    public function deleteAllEmails()
+    public function deleteAllEmails(): void
     {
         try {
             $this->mailhog->request('DELETE', '/api/v1/messages');
@@ -109,7 +110,7 @@ public function deleteAllEmails()
      *
      * Accessible from tests, fetches all emails
      */
-    public function fetchEmails()
+    public function fetchEmails(): void
     {
         $this->fetchedEmails = [];
 
@@ -133,7 +134,7 @@ public function fetchEmails()
      *
      * @param string $address Recipient address' inbox
      */
-    public function accessInboxFor($address)
+    public function accessInboxFor(string $address): void
     {
         $inbox = [];
 
@@ -160,7 +161,7 @@ public function accessInboxFor($address)
      *
      * @param string $address Recipient address' inbox
      */
-    public function accessInboxForTo($address)
+    public function accessInboxForTo(string $address): void
     {
         $inbox = [];
 
@@ -179,7 +180,7 @@ public function accessInboxForTo($address)
      *
      * @param string $address Recipient address' inbox
      */
-    public function accessInboxForCc($address)
+    public function accessInboxForCc(string $address): void
     {
         $inbox = [];
 
@@ -198,7 +199,7 @@ public function accessInboxForCc($address)
      *
      * @param string $address Recipient address' inbox
      */
-    public function accessInboxForBcc($address)
+    public function accessInboxForBcc(string $address): void
     {
         $inbox = [];
 
@@ -215,7 +216,7 @@ public function accessInboxForBcc($address)
      *
      * Pops the most recent unread email and assigns it as the email to conduct tests on
      */
-    public function openNextUnreadEmail()
+    public function openNextUnreadEmail(): void
     {
         $this->openedEmail = $this->getMostRecentUnreadEmail();
     }
@@ -226,9 +227,9 @@ public function openNextUnreadEmail()
      * Main method called by the tests, providing either the currently open email or the next unread one
      *
      * @param bool $fetchNextUnread Goes to the next Unread Email
-     * @return mixed Returns a JSON encoded Email
+     * @return object Returns a JSON encoded Email
      */
-    protected function getOpenedEmail($fetchNextUnread = false)
+    protected function getOpenedEmail(bool $fetchNextUnread = false): object
     {
         if ($fetchNextUnread || $this->openedEmail == null) {
             $this->openNextUnreadEmail();
@@ -242,9 +243,9 @@ protected function getOpenedEmail($fetchNextUnread = false)
      *
      * Pops the most recent unread email, fails if the inbox is empty
      *
-     * @return mixed Returns a JSON encoded Email
+     * @return object Returns a JSON encoded Email
      */
-    protected function getMostRecentUnreadEmail()
+    protected function getMostRecentUnreadEmail(): object
     {
         if (empty($this->unreadInbox)) {
             $this->fail('Unread Inbox is Empty');
@@ -260,9 +261,9 @@ protected function getMostRecentUnreadEmail()
      * Returns the full content of an email
      *
      * @param string $id ID from the header
-     * @return mixed Returns a JSON encoded Email
+     * @return object Returns a JSON encoded Email
      */
-    protected function getFullEmail($id)
+    protected function getFullEmail(string $id): object
     {
         try {
             $response = $this->mailhog->request('GET', "/api/v1/messages/{$id}");
@@ -277,11 +278,8 @@ protected function getFullEmail($id)
      * Get Email Subject
      *
      * Returns the subject of an email
-     *
-     * @param mixed $email Email
-     * @return string Subject
      */
-    protected function getEmailSubject($email)
+    protected function getEmailSubject(object $email): string
     {
         return $this->getDecodedEmailProperty($email, $email->Content->Headers->Subject[0]);
     }
@@ -290,11 +288,8 @@ protected function getEmailSubject($email)
      * Get Email Body
      *
      * Returns the body of an email
-     *
-     * @param mixed $email Email
-     * @return string Body
      */
-    protected function getEmailBody($email)
+    protected function getEmailBody(object $email): string
     {
         return $this->getDecodedEmailProperty($email, $email->Content->Body);
     }
@@ -303,11 +298,8 @@ protected function getEmailBody($email)
      * Get Email To
      *
      * Returns the string containing the persons included in the To field
-     *
-     * @param mixed $email Email
-     * @return string To
      */
-    protected function getEmailTo($email)
+    protected function getEmailTo(object $email): string
     {
         return $this->getDecodedEmailProperty($email, $email->Content->Headers->To[0]);
     }
@@ -316,11 +308,8 @@ protected function getEmailTo($email)
      * Get Email CC
      *
      * Returns the string containing the persons included in the CC field
-     *
-     * @param mixed $email Email
-     * @return string CC
      */
-    protected function getEmailCC($email)
+    protected function getEmailCC(object $email): string
     {
         $emailCc = '';
         if (isset($email->Content->Headers->Cc)) {
@@ -333,11 +322,8 @@ protected function getEmailCC($email)
      * Get Email BCC
      *
      * Returns the string containing the persons included in the BCC field
-     *
-     * @param mixed $email Email
-     * @return string BCC
      */
-    protected function getEmailBCC($email)
+    protected function getEmailBCC(object $email): string
     {
         $emailBcc = '';
         if (isset($email->Content->Headers->Bcc)) {
@@ -350,11 +336,8 @@ protected function getEmailBCC($email)
      * Get Email Recipients
      *
      * Returns the string containing all of the recipients, such as To, CC and if provided BCC
-     *
-     * @param mixed $email Email
-     * @return string Recipients
      */
-    protected function getEmailRecipients($email)
+    protected function getEmailRecipients(object $email): string
     {
         $recipients = [];
         if (isset($email->Content->Headers->To)) {
@@ -376,11 +359,8 @@ protected function getEmailRecipients($email)
      * Get Email Sender
      *
      * Returns the string containing the sender of the email
-     *
-     * @param mixed $email Email
-     * @return string Sender
      */
-    protected function getEmailSender($email)
+    protected function getEmailSender(object $email): string
     {
         return $this->getDecodedEmailProperty($email, $email->Content->Headers->From[0]);
     }
@@ -389,11 +369,8 @@ protected function getEmailSender($email)
      * Get Email Reply To
      *
      * Returns the string containing the address to reply to
-     *
-     * @param mixed $email Email
-     * @return string ReplyTo
      */
-    protected function getEmailReplyTo($email)
+    protected function getEmailReplyTo(object $email): string
     {
         return $this->getDecodedEmailProperty($email, $email->Content->Headers->{'Reply-To'}[0]);
     }
@@ -402,22 +379,16 @@ protected function getEmailReplyTo($email)
      * Get Email Priority
      *
      * Returns the priority of the email
-     *
-     * @param mixed $email Email
-     * @return string Priority
      */
-    protected function getEmailPriority($email)
+    protected function getEmailPriority(object $email): string
     {
         return $this->getDecodedEmailProperty($email, $email->Content->Headers->{'X-Priority'}[0]);
     }
 
     /**
      * Returns the decoded email property
-     *
-     * @param string $property
-     * @return string
      */
-    protected function getDecodedEmailProperty($email, $property)
+    protected function getDecodedEmailProperty(object $email, string $property): string
     {
         if ((string)$property != '') {
             if (!empty($email->Content->Headers->{'Content-Transfer-Encoding'}) &&
@@ -453,9 +424,9 @@ protected function getDecodedEmailProperty($email, $property)
      *
      * Sets the current inbox to work on, also create a copy of it to handle unread emails
      *
-     * @param array $inbox Inbox
+     * @param array<object> $inbox Inbox
      */
-    protected function setCurrentInbox($inbox)
+    protected function setCurrentInbox(array $inbox): void
     {
         $this->currentInbox = $inbox;
         $this->unreadInbox = $inbox;
@@ -466,9 +437,9 @@ protected function setCurrentInbox($inbox)
      *
      * Returns the complete current inbox
      *
-     * @return array Current Inbox
+     * @return array<object> Current Inbox
      */
-    protected function getCurrentInbox()
+    protected function getCurrentInbox(): array
     {
         return $this->currentInbox;
     }
@@ -478,9 +449,9 @@ protected function getCurrentInbox()
      *
      * Returns the inbox containing unread emails
      *
-     * @return array Unread Inbox
+     * @return array<object> Unread Inbox
      */
-    protected function getUnreadInbox()
+    protected function getUnreadInbox(): array
     {
         return $this->unreadInbox;
     }
@@ -490,9 +461,9 @@ protected function getUnreadInbox()
      *
      * Sorts the inbox based on the timestamp
      *
-     * @param array $inbox Inbox to sort
+     * @param array<object> $inbox Inbox to sort
      */
-    protected function sortEmails($inbox)
+    protected function sortEmails(array $inbox): void
     {
         usort($inbox, [$this, 'sortEmailsByCreationDatePredicate']);
     }
@@ -501,12 +472,8 @@ protected function sortEmails($inbox)
      * Get Email To
      *
      * Returns the string containing the persons included in the To field
-     *
-     * @param mixed $emailA Email
-     * @param mixed $emailB Email
-     * @return int Which email should go first
      */
-    public static function sortEmailsByCreationDatePredicate($emailA, $emailB)
+    public static function sortEmailsByCreationDatePredicate(object $emailA, object $emailB): int
     {
         $sortKeyA = $emailA->Content->Headers->Date;
         $sortKeyB = $emailB->Content->Headers->Date;
diff --git a/src/TestsEmails.php b/src/TestsEmails.php
index 9ff7b10..f17d46c 100644
--- a/src/TestsEmails.php
+++ b/src/TestsEmails.php
@@ -17,7 +17,7 @@ trait TestsEmails
      *
      * Checks if there are any emails in the inbox
      */
-    public function haveEmails()
+    public function haveEmails(): void
     {
         $currentInbox = $this->getCurrentInbox();
         $this->assertGreaterThan(0, count($currentInbox));
@@ -29,7 +29,7 @@ public function haveEmails()
      * Checks that the amount of emails in the inbox is exactly $expected
      * @params int $expected Number of expected emails
      */
-    public function haveNumberOfEmails($expected)
+    public function haveNumberOfEmails(int $expected): void
     {
         $currentInbox = $this->getCurrentInbox();
         $this->assertEquals($expected, count($currentInbox));
@@ -40,7 +40,7 @@ public function haveNumberOfEmails($expected)
      *
      * Checks that there are no emails in the inbox
      */
-    public function dontHaveEmails()
+    public function dontHaveEmails(): void
     {
         $currentInbox = $this->getCurrentInbox();
         $this->assertEquals(0, count($currentInbox));
@@ -51,7 +51,7 @@ public function dontHaveEmails()
      *
      * Checks that there is at least one unread email
      **/
-    public function haveUnreadEmails()
+    public function haveUnreadEmails(): void
     {
         $unreadInbox = $this->getUnreadInbox();
         $this->assertGreaterThan(0, count($unreadInbox));
@@ -63,7 +63,7 @@ public function haveUnreadEmails()
      * Checks that the amount of emails in the unread inbox is exactly $expected
      * @params int $expected Number of expected emails
      */
-    public function haveNumberOfUnreadEmails($expected)
+    public function haveNumberOfUnreadEmails(int $expected): void
     {
         $unreadInbox = $this->getUnreadInbox();
         $this->assertEquals($expected, count($unreadInbox));
@@ -74,7 +74,7 @@ public function haveNumberOfUnreadEmails($expected)
      *
      * Checks that there are no unread emails in the inbox
      */
-    public function dontHaveUnreadEmails()
+    public function dontHaveUnreadEmails(): void
     {
         $unreadInbox = $this->getUnreadInbox();
         $this->assertEquals(0, count($unreadInbox));
@@ -87,7 +87,7 @@ public function dontHaveUnreadEmails()
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailBody($expected)
+    public function seeInOpenedEmailBody(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailBody($email, $expected);
@@ -100,7 +100,7 @@ public function seeInOpenedEmailBody($expected)
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailSubject($expected)
+    public function seeInOpenedEmailSubject(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailSubject($email, $expected);
@@ -113,7 +113,7 @@ public function seeInOpenedEmailSubject($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailBody($expected)
+    public function dontSeeInOpenedEmailBody(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailBody($email, $expected);
@@ -126,7 +126,7 @@ public function dontSeeInOpenedEmailBody($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailSubject($expected)
+    public function dontSeeInOpenedEmailSubject(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailSubject($email, $expected);
@@ -137,10 +137,10 @@ public function dontSeeInOpenedEmailSubject($expected)
      *
      * Checks that the body of $email contains $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailBody($email, $expected)
+    public function seeInEmailBody(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailBody($email), 'Email Body Contains');
     }
@@ -150,10 +150,10 @@ public function seeInEmailBody($email, $expected)
      *
      * Checks that the body of $email does not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailBody($email, $expected)
+    public function dontSeeInEmailBody(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailBody($email), "Email Body Doesn't Contain");
     }
@@ -163,10 +163,10 @@ public function dontSeeInEmailBody($email, $expected)
      *
      * Checks that the subject of $email contains $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailSubject($email, $expected)
+    public function seeInEmailSubject(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailSubject($email), 'Email Subject Contains');
     }
@@ -176,10 +176,10 @@ public function seeInEmailSubject($email, $expected)
      *
      * Checks that the subject of $email does not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailSubject($email, $expected)
+    public function dontSeeInEmailSubject(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailSubject($email), "Email Subject Doesn't Contain");
     }
@@ -191,7 +191,7 @@ public function dontSeeInEmailSubject($email, $expected)
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailSender($expected)
+    public function seeInOpenedEmailSender(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailSender($email, $expected);
@@ -204,7 +204,7 @@ public function seeInOpenedEmailSender($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailSender($expected)
+    public function dontSeeInOpenedEmailSender(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailSender($email, $expected);
@@ -215,10 +215,10 @@ public function dontSeeInOpenedEmailSender($expected)
      *
      * Checks if the sender of $email contains $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailSender($email, $expected)
+    public function seeInEmailSender(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailSender($email));
     }
@@ -228,10 +228,10 @@ public function seeInEmailSender($email, $expected)
      *
      * Checks if the sender of $email does not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailSender($email, $expected)
+    public function dontSeeInEmailSender(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailSender($email));
     }
@@ -243,7 +243,7 @@ public function dontSeeInEmailSender($email, $expected)
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailReplyTo($expected)
+    public function seeInOpenedEmailReplyTo(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailReplyTo($email, $expected);
@@ -256,7 +256,7 @@ public function seeInOpenedEmailReplyTo($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailReplyTo($expected)
+    public function dontSeeInOpenedEmailReplyTo(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailReplyTo($email, $expected);
@@ -267,10 +267,10 @@ public function dontSeeInOpenedEmailReplyTo($expected)
      *
      * Checks if the ReplyTo of $email contains $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailReplyTo($email, $expected)
+    public function seeInEmailReplyTo(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailReplyTo($email));
     }
@@ -280,10 +280,10 @@ public function seeInEmailReplyTo($email, $expected)
      *
      * Checks if the ReplyTo of $email does not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailReplyTo($email, $expected)
+    public function dontSeeInEmailReplyTo(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailReplyTo($email));
     }
@@ -295,7 +295,7 @@ public function dontSeeInEmailReplyTo($email, $expected)
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailRecipients($expected)
+    public function seeInOpenedEmailRecipients(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailRecipients($email, $expected);
@@ -308,7 +308,7 @@ public function seeInOpenedEmailRecipients($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailRecipients($expected)
+    public function dontSeeInOpenedEmailRecipients(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailRecipients($email, $expected);
@@ -319,10 +319,10 @@ public function dontSeeInOpenedEmailRecipients($expected)
      *
      * Checks that the recipients of $email contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailRecipients($email, $expected)
+    public function seeInEmailRecipients(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailRecipients($email));
     }
@@ -332,10 +332,10 @@ public function seeInEmailRecipients($email, $expected)
      *
      * Checks that the recipients of $email do not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailRecipients($email, $expected)
+    public function dontSeeInEmailRecipients(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailRecipients($email));
     }
@@ -347,7 +347,7 @@ public function dontSeeInEmailRecipients($email, $expected)
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailToField($expected)
+    public function seeInOpenedEmailToField(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailToField($email, $expected);
@@ -360,7 +360,7 @@ public function seeInOpenedEmailToField($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailToField($expected)
+    public function dontSeeInOpenedEmailToField(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailToField($email, $expected);
@@ -371,10 +371,10 @@ public function dontSeeInOpenedEmailToField($expected)
      *
      * Checks that the To field of $email contains $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailToField($email, $expected)
+    public function seeInEmailToField(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailTo($email));
     }
@@ -384,10 +384,10 @@ public function seeInEmailToField($email, $expected)
      *
      * Checks that the To field of $email does not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailToField($email, $expected)
+    public function dontSeeInEmailToField(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailTo($email));
     }
@@ -399,7 +399,7 @@ public function dontSeeInEmailToField($email, $expected)
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailCCField($expected)
+    public function seeInOpenedEmailCCField(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailCCField($email, $expected);
@@ -412,7 +412,7 @@ public function seeInOpenedEmailCCField($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailCCField($expected)
+    public function dontSeeInOpenedEmailCCField(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailCCField($email, $expected);
@@ -423,10 +423,10 @@ public function dontSeeInOpenedEmailCCField($expected)
      *
      * Checks that the CC field of $email contains $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailCCField($email, $expected)
+    public function seeInEmailCCField(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailCC($email));
     }
@@ -436,10 +436,10 @@ public function seeInEmailCCField($email, $expected)
      *
      * Checks that the CC field of $email does not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailCCField($email, $expected)
+    public function dontSeeInEmailCCField(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailCC($email));
     }
@@ -453,7 +453,7 @@ public function dontSeeInEmailCCField($email, $expected)
      *
      * @param string $expected Text
      */
-    public function seeInOpenedEmailBCCField($expected)
+    public function seeInOpenedEmailBCCField(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailBCCField($email, $expected);
@@ -468,7 +468,7 @@ public function seeInOpenedEmailBCCField($expected)
      *
      * @param string $expected Text
      */
-    public function dontSeeInOpenedEmailBCCField($expected)
+    public function dontSeeInOpenedEmailBCCField(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailBCCField($email, $expected);
@@ -481,10 +481,10 @@ public function dontSeeInOpenedEmailBCCField($expected)
      *
      * Warning: it is possible for an email to have its BCC field empty, it doesn't mean that another instance of the same email doesn't exist.
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function seeInEmailBCCField($email, $expected)
+    public function seeInEmailBCCField(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailBCC($email));
     }
@@ -496,10 +496,10 @@ public function seeInEmailBCCField($email, $expected)
      *
      * Warning: it is possible for an email to have its BCC field empty, it doesn't mean that another instance of the same email doesn't exist.
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected Text
      */
-    public function dontSeeInEmailBCCField($email, $expected)
+    public function dontSeeInEmailBCCField(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailBCC($email));
     }
@@ -511,7 +511,7 @@ public function dontSeeInEmailBCCField($email, $expected)
      *
      * @param string $expected priority
      */
-    public function seeInOpenedEmailPriority($expected)
+    public function seeInOpenedEmailPriority(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->seeInEmailPriority($email, $expected);
@@ -524,7 +524,7 @@ public function seeInOpenedEmailPriority($expected)
      *
      * @param string $expected priority
      */
-    public function dontSeeInOpenedEmailPriority($expected)
+    public function dontSeeInOpenedEmailPriority(string $expected): void
     {
         $email = $this->getOpenedEmail();
         $this->dontSeeInEmailPriority($email, $expected);
@@ -535,10 +535,10 @@ public function dontSeeInOpenedEmailPriority($expected)
      *
      * Checks that the priority of $email contains $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected priority
      */
-    public function seeInEmailPriority($email, $expected)
+    public function seeInEmailPriority(object $email, string $expected): void
     {
         $this->assertStringContainsString($expected, $this->getEmailPriority($email));
     }
@@ -548,19 +548,19 @@ public function seeInEmailPriority($email, $expected)
      *
      * Checks that the priority of $email does not contain $expected
      *
-     * @param mixed $email a JSON encoded email
+     * @param object $email a JSON encoded email
      * @param string $expected priority
      */
-    public function dontSeeInEmailPriority($email, $expected)
+    public function dontSeeInEmailPriority(object $email, string $expected): void
     {
         $this->assertStringNotContainsString($expected, $this->getEmailPriority($email));
     }
 
     /**
      * @param string $content_type_alternative      MIME-part Content-Type
-     * @return string Body
+     * @return string|null Body
      */
-    public function grabBodyFromEmail($content_type_alternative = null)
+    public function grabBodyFromEmail(string $content_type_alternative = null): ?string
     {
         $email = $this->getOpenedEmail();