Fix Wordpress Contact Form & Email Submission Error

Troubleshooting I have a WordPress website built with Elementor Pro. My contact form is currently not working. When visitors submit the form, it returns "Submission Failed." I have also noticed a WordPress notification saying WP Mail SMTP has recently failed to send emails... (Budget: £30 - £75 GBP, Jobs: CSS, Elementor, HTML, PHP, Troubleshooting, Web Design, Web Development, WordPress)