I've been building a one-page business website with a contact form that submits to the business' email (using Nodemailer).

I've managed to get that part of it working; however, after the user submits the form, there is no way of knowing whether it sent successfully or not - is there a way I can implement this? (I'm quite new to web development!)

So far I've been following this tutorial: https://lo-victoria.com/how-to-build-a-contact-form-with-javascript-and-nodemailer

Any help is greatly appreciated!

Client-side code

const form = document.getElementById("contactForm");


const formEvent = form.addEventListener("submit", (event) => {
    event.preventDefault();

    
    let mail = new FormData(form);


    sendMail(mail);

    form.reset()
})

const sendMail = (mail) => {
    
    fetch("/", {
        method: "post", 
        body: mail, 

    }).then((response) => {
        return response.json();
    });
};

Nodemailer code

const transporter = nodemailer.createTransport({
    service: "gmail",
    auth: {
        user: process.env.EMAIL,
        pass: process.env.PASS,
    },
});

transporter.verify(function (error, success) {
    if (error) {
        console.log(error);
    } else {
        console.log("Server is ready to take our messages");
    }
});

app.post("/send", (req, res) => {
    
    let form = new multiparty.Form();
    let data = {};
    form.parse(req, function (err, fields) {
        console.log(fields);
        Object.keys(fields).forEach(function (property) {
            data[property] = fields[property].toString();
        });

        
        const mail = {
            sender: `${data.name} <${data.email}>`,
            to: process.env.EMAIL,
            subject: data.subject,
            text: `${data.name} <${data.email}> \n${data.message}`,
        };

       
        transporter.sendMail(mail, (err, data) => {
            if (err) {
                console.log(err);
                res.status(500).send("Something went wrong.");
            } else {
                res.status(200).send("Email successfully sent to recipient!");
            }
        });
    });
});