Fix WordPress Contact Form and Ongoing Website Support

I’m looking for a skilled, affordable developer for occasional website support. Currently, my immediate need is to fix the contact form on my WordPress site (whitestrawberry.co.uk). When visitors hit Submit, they see the error: “There was an error trying to send your message... (Budget: £10 - £20 GBP, Jobs: Email Handling, HTML, MySQL, PHP, SMTP, Website Optimization, WordPress, WordPress Plugin)