Forward emails to SendGrid and log IP of senders

sendMail.js

// Publish it as a Google App Script Web App to forward email from the contact form to your email using SendGrid
// This is intended for use with https://github.com/misterfresh/react-drive-cms

var sendGridApiKey =
    'YOUR-SENDGRID-API-KEY'
var sendGridVerifiedSenderEmail = 'YOUR-SENDGRID-VERIFIED-SENDER-EMAIL'
var sendGridVerifiedSenderName = 'YOUR-SENDGRID-VERIFIED-SENDER-NAME'
var contactEmail = 'YOUR-CONTACT-EMAIL'
var contactName = 'YOUR-CONTACT-NAME'
var visitorsSpreadsheetName = 'Visitors'

// this function will receive the incoming request from the client posting from the form
function doGet(request) {
    var formValues = request.parameter
    var messageToContact = ''
    messageToContact += '<h4>Name: ' + formValues.name + '</h4>'
    messageToContact += '<h4>Company: ' + formValues.company + '</h4>'
    messageToContact += '<h4>Email: ' + formValues.email + '</h4>'
    messageToContact += '<h4>Phone: ' + formValues.phone + '</h4>'
    messageToContact += '<h4>Message: <p>' + formValues.message + '</p></h4>'

    var response = sendMail(
        {
            email: contactEmail,
            name: contactName,
        },
        formValues.name + ' inquires about ReactDrive CMS',
        messageToContact
    )
    var result = {
        code: response.getResponseCode(),
        headers: response.getAllHeaders(),
        text: response.getContentText(),
    }

    var confirmationMessage = ''
    confirmationMessage += '<h4>Hello ' + formValues.name + ',</h4>'
    confirmationMessage +=
        '<h4>Your email has been sent to ' +
        contactName +
        ' at ' +
        contactEmail +
        ' with message:</h4>'
    confirmationMessage += '<h4><p>' + formValues.message + '</p></h4>'
    confirmationMessage += '<h4>Best regards,</h4>'
    confirmationMessage += '<h4>The ReactDrive CMS team</h4>'

    var confirmationResponse = sendMail(
        {
            email: formValues.email,
            name: formValues.name,
        },
        'Thanks for your interest in ReactDrive CMS, ' + formValues.name,
        confirmationMessage
    )
    var logInfo = {
        ip: request.parameter.ip,
        country: request.parameter.location,
        status: result.code,
    }
    logToSheet(logInfo)
    return ContentService.createTextOutput(
        request.parameters.callback + '(' + JSON.stringify(result) + ')'
    ).setMimeType(ContentService.MimeType.JAVASCRIPT)
}

// this function will post to Sendgrid the email information
function sendMail(destination, subject, htmlContent) {
    var message = {
        personalizations: [
            {
                to: [destination],
                subject: subject,
            },
        ],
        content: [
            {
                type: 'text/html',
                value: htmlContent,
            },
        ],
        from: {
            email: sendGridVerifiedSenderEmail,
            name: sendGridVerifiedSenderName,
        },
        reply_to: {
            email: sendGridVerifiedSenderEmail,
            name: sendGridVerifiedSenderName,
        },
    }
    var url = 'https://api.sendgrid.com/v3/mail/send'
    var options = {
        method: 'post',
        payload: JSON.stringify(message),
        contentType: 'application/json',
        headers: {
            'content-type': 'application/json',
            authorization: 'Bearer ' + sendGridApiKey,
        },
    }
    return UrlFetchApp.fetch(url, options)
}

// log user information to the Visitors spreadsheet
function logToSheet(logInfo) {
    var now = new Date()
    var strDateTime = [
        [
            AddZero(now.getDate()),
            AddZero(now.getMonth() + 1),
            now.getFullYear(),
        ].join('/'),
        [
            AddZero(now.getHours()),
            AddZero(now.getMinutes()),
            AddZero(now.getSeconds()),
        ].join(':'),
    ].join(' ')

    //Pad given value to the left with "0"
    function AddZero(num) {
        return num >= 0 && num < 10 ? '0' + num : num + ''
    }

    var visitorsSheets = DriveApp.getFilesByName(visitorsSpreadsheetName)
    if (visitorsSheets.hasNext()) {
        var visitorsFile = visitorsSheets.next()
        var visitorsSheet = SpreadsheetApp.open(visitorsFile)
    } else {
        return false
    }
    var emailsSheet = visitorsSheet.getSheets()[0]
    emailsSheet.insertRowsBefore(2, 1)
    emailsSheet
        .getRange('A2:D2')
        .setValues([[logInfo.ip, logInfo.country, logInfo.status, strDateTime]])
    return true
}