const x = createMimeMessage();
x.setSender({name: "Test", addr: "[email protected]"});
x.setRecipient("[email protected]");
x.setSubject("This is a test");

x.addMessage({
	contentType: 'text/html',
	data: "<h1>Lorem ipsum dolor sit amet...</h1>"
});

x.addMessage({
	contentType: 'text/plain',
	data: "Lorem ipsum dolor sit amet..."
});

x.addAttachment({
	inline: true,
	filename: "test.png",
	contentType: "image/png",
	data: "dGVzdA==",
	headers: { "Content-ID": "test" }
});

x.addAttachment({
	filename: "test.pdf",
	contentType: "application/pdf",
	data: "dGVzdA=="
});

console.log(x.asRaw());

Date: Wed, 06 Mar 2024 08:25:38 +0000
From: =?utf-8?B?VGVzdA==?= <[email protected]>
To: <[email protected]>
Message-ID: <[email protected]>
Subject: =?utf-8?B?VGhpcyBpcyBhIHRlc3Q=?=
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary=lu9hrte8tx

--lu9hrte8tx
Content-Type: multipart/related; boundary=11ntqiz482y

--11ntqiz482y
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 7bit

<h1>Lorem ipsum dolor sit amet...</h1>

--11ntqiz482y
Content-ID: <test>
Content-Type: image/png; name="test.png"
Content-Transfer-Encoding: base64
Content-Disposition: inline; filename="test.png"

dGVzdA==
--11ntqiz482y--
--lu9hrte8tx
Content-Type: application/pdf; name="test.pdf"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test.pdf"

dGVzdA==
--lu9hrte8tx--

Date: Wed, 06 Mar 2024 08:27:31 +0000
From: =?utf-8?B?VGVzdA==?= <[email protected]>
To: <[email protected]>
Message-ID: <[email protected]>
Subject: =?utf-8?B?VGhpcyBpcyBhIHRlc3Q=?=
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary=5fll5crxif3

--5fll5crxif3
Content-Type: multipart/alternative; boundary=qqzy1z2de9f

--qqzy1z2de9f
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

Lorem ipsum dolor sit amet...

--qqzy1z2de9f
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 7bit

<h1>Lorem ipsum dolor sit amet...</h1>

--qqzy1z2de9f--
--5fll5crxif3
Content-ID: <test>
Content-Type: image/png; name="test.png"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test.png"

dGVzdA==

--5fll5crxif3
Content-Type: application/pdf; name="test.pdf"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test.pdf"

dGVzdA==
--5fll5crxif3--