diff --git a/src/Appwrite/Event/Mail.php b/src/Appwrite/Event/Mail.php
index 95fffa90d8..47c9125c01 100644
--- a/src/Appwrite/Event/Mail.php
+++ b/src/Appwrite/Event/Mail.php
@@ -317,11 +317,12 @@ class Mail extends Event
     public function setAttachment(string $content, string $filename, string $encoding = 'base64', string $type = 'plain/text')
     {
         $this->attachment = [
-            'content' => $content,
+            'content' => base64_encode($content),
             'filename' => $filename,
             'encoding' => $encoding,
             'type' => $type,
         ];
+        return $this;
     }
 
     public function getAttachment(): array
diff --git a/src/Appwrite/Platform/Workers/Mails.php b/src/Appwrite/Platform/Workers/Mails.php
index bb55133c0b..9018f219ae 100644
--- a/src/Appwrite/Platform/Workers/Mails.php
+++ b/src/Appwrite/Platform/Workers/Mails.php
@@ -92,7 +92,7 @@ class Mails extends Action
         $mail->AltBody = \strip_tags($body);
         if (!empty($attachment['content'] ?? '')) {
             $mail->AddStringAttachment(
-                $attachment['content'],
+                base64_decode($attachment['content']),
                 $attachment['filename'] ?? 'unknown.file',
                 $attachment['encoding'] ?? PHPMailer::ENCODING_BASE64,
                 $attachment['type'] ?? 'plain/text'