gmail with multiple attachments not working

Question

When mail is sent with multiple attachments using gmail api, mail is not going properly. Attachments are not going in mail, instead some code is going in mail. I am using node js and request-promise module for achieving this.

I have tried sending attachments by setting boundaries on attachments. Here is the piece of code that I have written.

let user = await db.model('User').findOne({ _id: userId });
    let from = user.crmOptions.email;
    let mailString = '';
    for (let i in req.files) {
      mailString += '--boundary_mail1\n' + ','
      mailString += `Content-Type: ${req.files[i].mimetype}\n` + ','
      mailString += `Content-Disposition: attachment; filename="${req.files[i].filename}"\n` + ','
      mailString += "Content-Transfer-Encoding: base64\n\n" + ','
      mailString += `${fs.readFileSync(req.files[i].path).toString('base64')}` + ',' + '\n'
      if (i !== req.files.length - 1)
      mailString += ','
    }    
    let raw = [
      'MIME-Version: 1.0\n',
      "to: ", req.body.to, "\n",
      "from: ", from, "\n",
      "cc: ", req.body.cc ? req.body.cc : '', "\n",
      "bcc: ", req.body.bcc ? req.body.bcc : '', "\n",
      "subject: ", req.body.subject ? req.body.subject : '', "\n",
      "Content-Type: multipart/mixed; boundary=boundary_mail1\n\n",

      "--boundary_mail1\n",
      "Content-Type: multipart/alternative; boundary=boundary_mail2\n\n",

      "--boundary_mail2\n",
      "Content-Type: text/html; charset=UTF-8\n",
      "Content-Transfer-Encoding: quoted-printable\n\n",
      req.body.message = req.body.message ? req.body.message : '', "\n\n",
      "--boundary_mail2--\n",
      mailString,
      '--boundary_mail1--',
    ].join('');
    const id = 'me';
    let options = {
      url: "https://www.googleapis.com/upload/gmail/v1/users/" + id + "/messages/send?uploadType=multipart",
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${user.crmOptions.access_token}`,
        'Content-Type': 'message/rfc822'
      },
      body: raw
    };

await request(options).then(async body => {
  console.log("Body: ", body);
}).catch(err => {
  console.log("Error: ", err);
})

I want email to be delivered with multiple attachments. But I am not able to send mail with single attachment also. Could anyone help me resolve the issue.

You can check this [SO post](https://stackoverflow.com/questions/26582811/gmail-python-multiple-attachments) to get idea or process on how send multiple attachments. But it uses python code. — Jessica Rodriguez, Jan 08 '19 at 13:53
@jess Thank you for reply, but I don't know python. If any javascript or node js code is there it is better for understanding. — Dinesh Sathrasala, Jan 08 '19 at 14:26
@jess could you have a look at this issue: https://stackoverflow.com/questions/54018048/gmail-with-table-in-message-body-is-not-getting-displayed-in-mail-but-table-data — Dinesh Sathrasala, Jan 09 '19 at 04:20

score 2 · Accepted Answer · answered Jan 09 '19 at 06:06

I found out issue guys. Just removed unwanted commas and its working. here is the modified code.

let user = await db.model('User').findOne({ _id: userId });
    let from = user.crmOptions.email;
    let mailString = '';
    for (let i in req.files) {
      mailString += '--boundary_mail1\n'
      mailString += `Content-Type: ${req.files[i].mimetype}\n`
      mailString += `Content-Disposition: attachment; filename="${req.files[i].filename}"\n`
      mailString += "Content-Transfer-Encoding: base64\n\n"
      mailString += `${fs.readFileSync(req.files[i].path).toString('base64')}` + '\n'
    }
    let raw = [
      'MIME-Version: 1.0\n',
      "to: ", req.body.to, "\n",
      "from: ", from, "\n",
      "cc: ", req.body.cc ? req.body.cc : '', "\n",
      "bcc: ", req.body.bcc ? req.body.bcc : '', "\n",
      "subject: ", req.body.subject ? req.body.subject : '', "\n",
      "Content-Type: multipart/mixed; boundary=boundary_mail1\n\n",

      "--boundary_mail1\n",
      "Content-Type: multipart/alternative; boundary=boundary_mail2\n\n",

      "--boundary_mail2\n",
      "Content-Type: text/html; charset=UTF-8\n",
      "Content-Transfer-Encoding: quoted-printable\n\n",
      req.body.message = req.body.message ? req.body.message : '', "\n\n",
      "--boundary_mail2--\n",
      mailString,
      '--boundary_mail1--',
    ].join('');
    const id = 'me';
    let options = {
      url: "https://www.googleapis.com/upload/gmail/v1/users/" + id + "/messages/send?uploadType=multipart",
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${user.crmOptions.access_token}`,
        'Content-Type': 'message/rfc822'
      },
      body: raw
    };
await request(options).then(async body => {
  console.log("Body: ", body);
}).catch(err => {
  console.log("Error: ", err);
})

score 0 · Answer 2 · answered Mar 07 '23 at 11:20

This solution is working in Nodejs install google API's library

const { google } = require('googleapis');

static async sendEmail(refresh_token, to, subject, message, files) {
    const oauth2Client = new google.auth.OAuth2(
                config.get('service:google:client_id'),
                config.get('service:google:client_secret'),
                `${config.get('hostname')}/webhook/google/oauth-redirect`
            );

            // get access_token
            oauth2Client.setCredentials({
                refresh_token
            });

            // init gmail api
            const gmail = google.gmail({
                version: 'v1',
                auth: oauth2Client
            });

            

            const raw = await this.makeBodyWithAttachments(to, subject, message, files);

            const res = await gmail.users.messages.send({
                userId: 'me',
                uploadType: 'multipart',
                requestBody: {
                    raw
                }
            });
}

static async makeBodyWithAttachments(to, subject, message, files) {

    let mailString = '';
    for (let i in files) {
        mailString += '--boundary_mail1\n'
        mailString += `Content-Type: ${files[i].mimetype}\n`
        mailString += `Content-Disposition: attachment; filename="${files[i].filename}"\n`
        mailString += "Content-Transfer-Encoding: base64\n\n"
        mailString += `${fs.readFileSync(files[i].path).toString('base64')}` + '\n'
    }

    let raw = [
    'MIME-Version: 1.0\n',
    "to: ", to, "\n",
    "subject: ", subject ? subject : '', "\n",
    "Content-Type: multipart/mixed; boundary=boundary_mail1\n\n",

    "--boundary_mail1\n",
    "Content-Type: multipart/alternative; boundary=boundary_mail2\n\n",

    "--boundary_mail2\n",
    "Content-Type: text/html; charset=UTF-8\n",
    "Content-Transfer-Encoding: quoted-printable\n\n",
    message = message ? message : '', "\n\n",
    "--boundary_mail2--\n",
    mailString,
    '--boundary_mail1--',
    ].join('');

    return Buffer(raw).toString("base64").replace(/\+/g, '-').replace(/\//g, '_');
}

gmail with multiple attachments not working

2 Answers2

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