diff --git a/src/MIMEMessage.ts b/src/MIMEMessage.ts
index 7c9eec1..3e8ec55 100644
--- a/src/MIMEMessage.ts
+++ b/src/MIMEMessage.ts
@@ -113,7 +113,7 @@ export class MIMEMessage {
 
         let data = ''
 
-        if (plaintext && html && !this.hasInlineAttachments() && this.hasAttachments()) {
+        if (plaintext && html && (this.hasInlineAttachments() || this.hasAttachments())) {
             data = '--' + boundary + eol +
                 'Content-Type: multipart/alternative; boundary=' + this.boundaries.alt + eol +
                 eol +
@@ -124,9 +124,6 @@ export class MIMEMessage {
                 html.dump() + eol +
                 eol +
                 '--' + this.boundaries.alt + '--'
-        } else if (plaintext && html && this.hasInlineAttachments()) {
-            data = '--' + boundary + eol +
-                html.dump()
         } else if (plaintext && html) {
             data = '--' + boundary + eol +
                 plaintext.dump() + eol +
diff --git a/tests/MIMEMessage.spec.js b/tests/MIMEMessage.spec.js
index d30f14c..6eb5017 100644
--- a/tests/MIMEMessage.spec.js
+++ b/tests/MIMEMessage.spec.js
@@ -193,7 +193,52 @@ test('generates plain text and html mixed message with an attachment', () => {
     )
 })
 
-test('sending only an attachment, without content isn not allowed', async () => {
+test('generates plain text and html related message with an inline attachment', () => {
+    const msg = new MIMEMessage(envctx)
+    msg.boundaries = {related: 'abcdef', alt: 'qwerty'}
+    msg.setHeader('Date', 'Wed, 22 Mar 2023 23:36:33 +0000')
+    msg.setHeader('Message-ID', '<oliusb0xvxc@mail.com>')
+    msg.setSender('test@mail.com')
+    msg.setSubject('Lorem Ipsum')
+    msg.addMessage({contentType: 'text/plain', data: 'hello there'})
+    msg.addMessage({contentType: 'text/html', data: 'hello there <b>Murat</b>'})
+    msg.addAttachment({
+        inline: true,
+        contentType: 'image/jpg',
+        filename: 'sample.jpg',
+        data: sampleImageBase64
+    })
+
+    expect(msg.hasInlineAttachments()).toBe(true);
+    expect(msg.getMessageByType("text/plain")?.data).toBe("hello there")
+
+    expect(msg.asRaw()).toBe('Date: Wed, 22 Mar 2023 23:36:33 +0000' + envctx.eol +
+        'From: <test@mail.com>' + envctx.eol +
+        'Message-ID: <oliusb0xvxc@mail.com>' + envctx.eol +
+        'Subject: =?utf-8?B?TG9yZW0gSXBzdW0=?=' + envctx.eol +
+        'MIME-Version: 1.0' + envctx.eol +
+        'Content-Type: multipart/related; boundary=abcdef' + envctx.eol + envctx.eol +
+        '--abcdef' + envctx.eol +
+        'Content-Type: multipart/alternative; boundary=qwerty' + envctx.eol + envctx.eol +
+        '--qwerty' + envctx.eol +
+        'Content-Type: text/plain; charset=UTF-8' + envctx.eol +
+        'Content-Transfer-Encoding: 7bit' + envctx.eol + envctx.eol +
+        'hello there' + envctx.eol + envctx.eol +
+        '--qwerty' + envctx.eol +
+        'Content-Type: text/html; charset=UTF-8' + envctx.eol +
+        'Content-Transfer-Encoding: 7bit' + envctx.eol + envctx.eol +
+        'hello there <b>Murat</b>' + envctx.eol + envctx.eol +
+        '--qwerty--' + envctx.eol + envctx.eol +
+        '--abcdef' + envctx.eol +
+        'Content-Type: image/jpg; name="sample.jpg"' + envctx.eol +
+        'Content-Transfer-Encoding: base64' + envctx.eol +
+        'Content-Disposition: inline; filename="sample.jpg"' + envctx.eol + envctx.eol +
+        sampleImageBase64 + envctx.eol +
+        '--abcdef--'
+    )
+})
+
+test('sending only an attachment, without content is not allowed', async () => {
     const msg = new MIMEMessage(envctx)
     msg.setHeader('Date', 'Wed, 22 Mar 2023 23:36:33 +0000')
     msg.setHeader('Message-ID', '<oliusb0xvxc@mail.com>')