Safe to use? (Not leaking credentials to client)

// get the smtp credentials from the environment variables
const smtpCredentials = {
    host: process.env.SMTP_HOST!,
    port: parseInt(process.env.SMTP_PORT!),
    auth: {
        user: process.env.SMTP_USER!,
        pass: process.env.SMTP_PASSWORD!,
    },
};

// create a transporter object using the default SMTP transport
const transporter = nodemailer.createTransport(smtpCredentials);

export const sendEmail = createServerFn({
    method: "POST",
})
.validator((data: { to: string; subject: string; text: string }) => {
    if (!data.to || !data.subject || !data.text) {
        throw new Error("Missing required fields");
    }
    return data;
})
.handler(async (ctx) => {
    const { to, subject, text } = ctx.data;
    console.log(`Sending email to ${to} with subject ${subject} and text ${text}`);
    const mailOptions = {
        from: `${process.env.SMTP_SENDER_NAME} <${process.env.SMTP_USER}>`,
....