diff --git a/ProcessMaker/Mail/MicrosoftGraphMessageConverter.php b/ProcessMaker/Mail/MicrosoftGraphMessageConverter.php
index e95a3ea281..a87205cdcc 100644
--- a/ProcessMaker/Mail/MicrosoftGraphMessageConverter.php
+++ b/ProcessMaker/Mail/MicrosoftGraphMessageConverter.php
@@ -31,6 +31,11 @@ public static function toSendMailPayload(Email $email): array
             $message['bccRecipients'] = $bccRecipients;
         }
 
+        $attachments = self::convertAttachments($email);
+        if ($attachments) {
+            $message['attachments'] = $attachments;
+        }
+
         return [
             'message' => $message,
             'saveToSentItems' => true,
@@ -52,4 +57,20 @@ private static function convertAddresses(array $addresses): array
             return ['emailAddress' => $emailAddress];
         }, $addresses);
     }
+
+    private static function convertAttachments(Email $email): array
+    {
+        $attachments = [];
+
+        foreach ($email->getAttachments() as $attachment) {
+            $attachments[] = [
+                '@odata.type' => '#microsoft.graph.fileAttachment',
+                'name' => $attachment->getFilename() ?: 'attachment',
+                'contentType' => $attachment->getMediaType() . '/' . $attachment->getMediaSubtype(),
+                'contentBytes' => base64_encode($attachment->getBody()),
+            ];
+        }
+
+        return $attachments;
+    }
 }
diff --git a/tests/unit/ProcessMaker/Mail/MicrosoftGraphMessageConverterTest.php b/tests/unit/ProcessMaker/Mail/MicrosoftGraphMessageConverterTest.php
new file mode 100644
index 0000000000..71d172a2ca
--- /dev/null
+++ b/tests/unit/ProcessMaker/Mail/MicrosoftGraphMessageConverterTest.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Tests\Unit\ProcessMaker\Mail;
+
+use ProcessMaker\Mail\MicrosoftGraphMessageConverter;
+use Symfony\Component\Mime\Email;
+use Tests\TestCase;
+
+class MicrosoftGraphMessageConverterTest extends TestCase
+{
+    public function testToSendMailPayloadIncludesFileAttachments()
+    {
+        $email = (new Email())
+            ->to('recipient@example.com')
+            ->subject('With attachment')
+            ->html('<p>Hello</p>')
+            ->attach('file-contents', 'report.txt', 'text/plain');
+
+        $payload = MicrosoftGraphMessageConverter::toSendMailPayload($email);
+
+        $this->assertSame('With attachment', $payload['message']['subject']);
+        $this->assertSame('HTML', $payload['message']['body']['contentType']);
+        $this->assertCount(1, $payload['message']['attachments']);
+        $this->assertSame([
+            '@odata.type' => '#microsoft.graph.fileAttachment',
+            'name' => 'report.txt',
+            'contentType' => 'text/plain',
+            'contentBytes' => base64_encode('file-contents'),
+        ], $payload['message']['attachments'][0]);
+    }
+
+    public function testToSendMailPayloadOmitsAttachmentsKeyWhenNonePresent()
+    {
+        $email = (new Email())
+            ->to('recipient@example.com')
+            ->subject('No attachment')
+            ->text('Hello');
+
+        $payload = MicrosoftGraphMessageConverter::toSendMailPayload($email);
+
+        $this->assertArrayNotHasKey('attachments', $payload['message']);
+    }
+}