diff --git a/app/config/errors.php b/app/config/errors.php
index e5c2d4e5bd..4cc8e734ee 100644
--- a/app/config/errors.php
+++ b/app/config/errors.php
@@ -811,6 +811,11 @@ return [
         'description' => 'Provider with the requested ID is of the incorrect type.',
         'code' => 400,
     ],
+    Exception::PROVIDER_MISSING_CREDENTIALS => [
+        'name' => Exception::PROVIDER_MISSING_CREDENTIALS,
+        'description' => 'Provider with the requested ID is missing credentials.',
+        'code' => 400,
+    ],
 
     /** Topics */
     Exception::TOPIC_NOT_FOUND => [
diff --git a/app/controllers/api/messaging.php b/app/controllers/api/messaging.php
index ef72be19cf..a6c2f923eb 100644
--- a/app/controllers/api/messaging.php
+++ b/app/controllers/api/messaging.php
@@ -62,10 +62,10 @@ App::post('/v1/messaging/providers/mailgun')
     ->param('domain', '', new Text(0), 'Mailgun Domain.', true)
     ->param('isEuRegion', null, new Boolean(), 'Set as EU region.', true)
     ->param('enabled', null, new Boolean(), 'Set as enabled.', true)
-    ->param('fromName', '', new Text(128), 'Sender Name.', true)
+    ->param('fromName', '', new Text(128, 0), 'Sender Name.', true)
     ->param('fromEmail', '', new Email(), 'Sender email address.', true)
-    ->param('replyToName', '', new Text(128), 'Name set in the reply to field for the mail. Default value is sender name. Reply to name must have reply to email as well.', true)
-    ->param('replyToEmail', '', new Text(128), 'Email set in the reply to field for the mail. Default value is sender email. Reply to email must have reply to name as well.', true)
+    ->param('replyToName', '', new Text(128, 0), 'Name set in the reply to field for the mail. Default value is sender name. Reply to name must have reply to email as well.', true)
+    ->param('replyToEmail', '', new Email(), 'Email set in the reply to field for the mail. Default value is sender email. Reply to email must have reply to name as well.', true)
     ->inject('queueForEvents')
     ->inject('dbForProject')
     ->inject('response')
@@ -101,7 +101,7 @@ App::post('/v1/messaging/providers/mailgun')
             \array_key_exists('isEuRegion', $credentials) &&
             \array_key_exists('apiKey', $credentials) &&
             \array_key_exists('domain', $credentials) &&
-            \array_key_exists('from', $options)
+            \array_key_exists('fromEmail', $options)
         ) {
             $enabled = true;
         } else {
@@ -150,10 +150,10 @@ App::post('/v1/messaging/providers/sendgrid')
     ->param('name', '', new Text(128), 'Provider name.')
     ->param('apiKey', '', new Text(0), 'Sendgrid API key.', true)
     ->param('enabled', null, new Boolean(), 'Set as enabled.', true)
-    ->param('fromName', '', new Text(128), 'Sender Name.', true)
+    ->param('fromName', '', new Text(128, 0), 'Sender Name.', true)
     ->param('fromEmail', '', new Email(), 'Sender email address.', true)
-    ->param('replyToName', '', new Text(128), 'Name set in the reply to field for the mail. Default value is sender name.', true)
-    ->param('replyToEmail', '', new Text(128), 'Email set in the reply to field for the mail. Default value is sender email.', true)
+    ->param('replyToName', '', new Text(128, 0), 'Name set in the reply to field for the mail. Default value is sender name.', true)
+    ->param('replyToEmail', '', new Email(), 'Email set in the reply to field for the mail. Default value is sender email.', true)
     ->inject('queueForEvents')
     ->inject('dbForProject')
     ->inject('response')
@@ -179,7 +179,7 @@ App::post('/v1/messaging/providers/sendgrid')
         if (
             $enabled === true
             && \array_key_exists('apiKey', $credentials)
-            && \array_key_exists('from', $options)
+            && \array_key_exists('fromEmail', $options)
         ) {
             $enabled = true;
         } else {
@@ -616,9 +616,13 @@ App::post('/v1/messaging/providers/fcm')
     ->inject('queueForEvents')
     ->inject('dbForProject')
     ->inject('response')
-    ->action(function (string $providerId, string $name, ?array $serviceAccountJSON, ?bool $enabled, Event $queueForEvents, Database $dbForProject, Response $response) {
+    ->action(function (string $providerId, string $name, array|string|null $serviceAccountJSON, ?bool $enabled, Event $queueForEvents, Database $dbForProject, Response $response) {
         $providerId = $providerId == 'unique()' ? ID::unique() : $providerId;
 
+        $serviceAccountJSON = \is_string($serviceAccountJSON)
+            ? \json_decode($serviceAccountJSON, true)
+            : $serviceAccountJSON;
+
         $credentials = [];
 
         if (!\is_null($serviceAccountJSON)) {
@@ -917,9 +921,10 @@ App::patch('/v1/messaging/providers/mailgun/:providerId')
         if ($provider->isEmpty()) {
             throw new Exception(Exception::PROVIDER_NOT_FOUND);
         }
-        $providerAttr = $provider->getAttribute('provider');
 
-        if ($providerAttr !== 'mailgun') {
+        $providerProvider = $provider->getAttribute('provider');
+
+        if ($providerProvider !== 'mailgun') {
             throw new Exception(Exception::PROVIDER_INCORRECT_TYPE);
         }
 
@@ -949,7 +954,7 @@ App::patch('/v1/messaging/providers/mailgun/:providerId')
 
         $credentials = $provider->getAttribute('credentials');
 
-        if ($isEuRegion === true || $isEuRegion === false) {
+        if (!\is_null($isEuRegion)) {
             $credentials['isEuRegion'] = $isEuRegion;
         }
 
@@ -963,19 +968,21 @@ App::patch('/v1/messaging/providers/mailgun/:providerId')
 
         $provider->setAttribute('credentials', $credentials);
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true &&
-                \array_key_exists('isEuRegion', $credentials) &&
-                \array_key_exists('apiKey', $credentials) &&
-                \array_key_exists('domain', $credentials) &&
-                \array_key_exists('from', $provider->getAttribute('options'))
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('isEuRegion', $credentials) &&
+                    \array_key_exists('apiKey', $credentials) &&
+                    \array_key_exists('domain', $credentials) &&
+                    \array_key_exists('fromEmail', $options)
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1054,17 +1061,19 @@ App::patch('/v1/messaging/providers/sendgrid/:providerId')
             ]);
         }
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true
-                && \array_key_exists('apiKey', $provider->getAttribute('credentials'))
-                && \array_key_exists('from', $provider->getAttribute('options'))
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('apiKey', $provider->getAttribute('credentials')) &&
+                    \array_key_exists('fromEmail', $provider->getAttribute('options'))
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1133,18 +1142,20 @@ App::patch('/v1/messaging/providers/msg91/:providerId')
 
         $provider->setAttribute('credentials', $credentials);
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true
-                && \array_key_exists('senderId', $credentials)
-                && \array_key_exists('authKey', $credentials)
-                && \array_key_exists('from', $provider->getAttribute('options'))
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('senderId', $credentials) &&
+                    \array_key_exists('authKey', $credentials) &&
+                    \array_key_exists('from', $provider->getAttribute('options'))
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1213,19 +1224,20 @@ App::patch('/v1/messaging/providers/telesign/:providerId')
 
         $provider->setAttribute('credentials', $credentials);
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true
-                && \array_key_exists('username', $credentials)
-                && \array_key_exists('password', $credentials)
-                && \array_key_exists('from', $provider->getAttribute('options'))
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('username', $credentials) &&
+                    \array_key_exists('password', $credentials) &&
+                    \array_key_exists('from', $provider->getAttribute('options'))
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1294,19 +1306,20 @@ App::patch('/v1/messaging/providers/textmagic/:providerId')
 
         $provider->setAttribute('credentials', $credentials);
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true
-                && \array_key_exists('username', $credentials)
-                && \array_key_exists('apiKey', $credentials)
-                && \array_key_exists('from', $provider->getAttribute('options'))
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('username', $credentials) &&
+                    \array_key_exists('apiKey', $credentials) &&
+                    \array_key_exists('from', $provider->getAttribute('options'))
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1375,19 +1388,20 @@ App::patch('/v1/messaging/providers/twilio/:providerId')
 
         $provider->setAttribute('credentials', $credentials);
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true
-                && \array_key_exists('accountSid', $credentials)
-                && \array_key_exists('authToken', $credentials)
-                && \array_key_exists('from', $provider->getAttribute('options'))
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('accountSid', $credentials) &&
+                    \array_key_exists('authToken', $credentials) &&
+                    \array_key_exists('from', $provider->getAttribute('options'))
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1456,19 +1470,20 @@ App::patch('/v1/messaging/providers/vonage/:providerId')
 
         $provider->setAttribute('credentials', $credentials);
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true
-                && \array_key_exists('apiKey', $credentials)
-                && \array_key_exists('apiSecret', $credentials)
-                && \array_key_exists('from', $provider->getAttribute('options'))
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('apiKey', $credentials) &&
+                    \array_key_exists('apiSecret', $credentials) &&
+                    \array_key_exists('from', $provider->getAttribute('options'))
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1501,7 +1516,7 @@ App::patch('/v1/messaging/providers/fcm/:providerId')
     ->inject('queueForEvents')
     ->inject('dbForProject')
     ->inject('response')
-    ->action(function (string $providerId, string $name, ?bool $enabled, ?array $serviceAccountJSON, Event $queueForEvents, Database $dbForProject, Response $response) {
+    ->action(function (string $providerId, string $name, ?bool $enabled, array|string|null $serviceAccountJSON, Event $queueForEvents, Database $dbForProject, Response $response) {
         $provider = $dbForProject->getDocument('providers', $providerId);
 
         if ($provider->isEmpty()) {
@@ -1518,17 +1533,25 @@ App::patch('/v1/messaging/providers/fcm/:providerId')
         }
 
         if (!\is_null($serviceAccountJSON)) {
-            $provider->setAttribute('credentials', ['serviceAccountJSON' => $serviceAccountJSON]);
+            $serviceAccountJSON = \is_string($serviceAccountJSON)
+                ? \json_decode($serviceAccountJSON, true)
+                : $serviceAccountJSON;
+
+            $provider->setAttribute('credentials', [
+                'serviceAccountJSON' => $serviceAccountJSON
+            ]);
         }
 
-        if ($enabled === true || $enabled === false) {
-            if ($enabled === true && \array_key_exists('serviceAccountJSON', $provider->getAttribute('credentials'))) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (\array_key_exists('serviceAccountJSON', $provider->getAttribute('credentials'))) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
@@ -1601,20 +1624,21 @@ App::patch('/v1/messaging/providers/apns/:providerId')
 
         $provider->setAttribute('credentials', $credentials);
 
-        if ($enabled === true || $enabled === false) {
-            if (
-                $enabled === true
-                && \array_key_exists('authKey', $credentials)
-                && \array_key_exists('authKeyId', $credentials)
-                && \array_key_exists('teamId', $credentials)
-                && \array_key_exists('bundleId', $credentials)
-            ) {
-                $enabled = true;
+        if (!\is_null($enabled)) {
+            if ($enabled) {
+                if (
+                    \array_key_exists('authKey', $credentials) &&
+                    \array_key_exists('authKeyId', $credentials) &&
+                    \array_key_exists('teamId', $credentials) &&
+                    \array_key_exists('bundleId', $credentials)
+                ) {
+                    $provider->setAttribute('enabled', true);
+                } else {
+                    throw new Exception(Exception::PROVIDER_MISSING_CREDENTIALS);
+                }
             } else {
-                $enabled = false;
+                $provider->setAttribute('enabled', false);
             }
-
-            $provider->setAttribute('enabled', $enabled);
         }
 
         $provider = $dbForProject->updateDocument('providers', $provider->getId(), $provider);
diff --git a/src/Appwrite/Extend/Exception.php b/src/Appwrite/Extend/Exception.php
index 183f4a812a..d81589ed9d 100644
--- a/src/Appwrite/Extend/Exception.php
+++ b/src/Appwrite/Extend/Exception.php
@@ -244,7 +244,7 @@ class Exception extends \Exception
     public const PROVIDER_NOT_FOUND                 = 'provider_not_found';
     public const PROVIDER_ALREADY_EXISTS            = 'provider_already_exists';
     public const PROVIDER_INCORRECT_TYPE            = 'provider_incorrect_type';
-    public const PROVIDER_INTERNAL_UPDATE_DISABLED  = 'provider_internal_update_disabled';
+    public const PROVIDER_MISSING_CREDENTIALS       = 'provider_missing_credentials';
 
     /** Topic */
     public const TOPIC_NOT_FOUND                    = 'topic_not_found';
diff --git a/tests/e2e/Services/Messaging/MessagingBase.php b/tests/e2e/Services/Messaging/MessagingBase.php
index 1a16674658..0e7fca8507 100644
--- a/tests/e2e/Services/Messaging/MessagingBase.php
+++ b/tests/e2e/Services/Messaging/MessagingBase.php
@@ -185,6 +185,32 @@ trait MessagingBase
         return $providers;
     }
 
+    public function testUpdateProviderMissingCredentialsThrows(): void
+    {
+        // Create new FCM provider with no serviceAccountJSON
+        $response = $this->client->call(Client::METHOD_POST, '/messaging/providers/fcm', [
+            'content-type' => 'application/json',
+            'x-appwrite-project' => $this->getProject()['$id'],
+            'x-appwrite-key' => $this->getProject()['apiKey'],
+        ], [
+            'providerId' => ID::unique(),
+            'name' => 'FCM3',
+        ]);
+
+        $this->assertEquals(201, $response['headers']['status-code']);
+
+        // Enable provider with no serviceAccountJSON
+        $response = $this->client->call(Client::METHOD_PATCH, '/messaging/providers/fcm/' . $response['body']['$id'], [
+            'content-type' => 'application/json',
+            'x-appwrite-project' => $this->getProject()['$id'],
+            'x-appwrite-key' => $this->getProject()['apiKey'],
+        ], [
+            'enabled' => true,
+        ]);
+
+        $this->assertEquals(400, $response['headers']['status-code']);
+    }
+
     /**
      * @depends testUpdateProviders
      */
@@ -197,7 +223,7 @@ trait MessagingBase
         ]);
 
         $this->assertEquals(200, $response['headers']['status-code']);
-        $this->assertEquals(\count($providers), \count($response['body']['providers']));
+        $this->assertEquals(10, \count($response['body']['providers']));
 
         return $providers;
     }