在reactjs中使用gmail api发送带有纯文本、附件和html的电子邮件

我目前正在尝试使用 reactjs 中的 gmail api 发送由 3 个组件组成的电子邮件：纯文本、附件和 html。现在使用我的代码发送电子邮件，我只能接收附件和 html。下面是我用来发送电子邮件的代码：

    for (i=0; i<email.attachment.length; i++) {
        let content = email.attachment[i].data.split(",")[1];
        let attachment = ['--012boundary01\r\n',
                         'Content-Type: ' + email.attachment[i].type + '\r\n',
                         'MIME-Version: 1.0\r\n',
                         'Content-Transfer-Encoding: base64\r\n',
                         'Content-Disposition: attachment; filename=' + email.attachment[i].name + '\r\n\r\n',
                          content, '\r\n\r\n'].join('');
        console.log(attachment)
        attachments += attachment
     };

     let mail = [
        'Content-Type: multipart/mixed; boundary="012boundary01"\r\n',
        'MIME-Version: 1.0\r\n',
        'To: ' + email.to + '\r\n',
        'Subject: ' + email.subject + '\r\n\r\n',
        '--012boundary01\r\n',
        'Content-Type: multipart/alternative; boundary=012boundary02\r\n\r\n',
        '--012boundary02\r\n',
        'Content-Type: text/plain; charset=UTF-8\r\n\r\n',
        email.body + '\r\n\r\n',
        '--012boundary02\r\n',
        'Content-Type: text/html; charset=UTF-8\r\n',
        'Content-Transfer-Encoding: quoted-printable\r\n\r\n',
        '<h1>HELLO</h1>\r\n\r\n',
        '--012boundary02--\r\n',

        attachments,

        '--012boundary01--'
     ].join('');

content 变量是我的附件的 base64 编码字符串。

最终的邮件变量将如下所示：

Content-Type: multipart/mixed; boundary="012boundary01"

MIME-Version: 1.0

To: [email protected]

Subject: test again

--012boundary01
Content-Type: multipart/alternative; boundary=012boundary02

--012boundary02
Content-Type: text/plain; charset=UTF-8

testing123

--012boundary02

Content-Type: text/html; charset=UTF-8

Content-Transfer-Encoding: quoted-printable

<h1>HELLO</h1>

--012boundary02--

--012boundary01

Content-Type: image/jpeg

MIME-Version: 1.0

Content-Transfer-Encoding: base64

Content-Disposition: attachment; filename=1x1_red_pixel.jpeg

(base64 encoded string here)