Hello,
My name is Mario, and I am interested in working with you. I have been working online for over ten years as a web developer, and I think I am the right person for the job.
I have developed over 200 websites using WordPress. I will fix the problem with your site in a timely fashion. I will also optimize the site, as a "thank you" for giving me this opportunity.
I will work tirelessly until you are satisfied with the final product.
Thank you for your time, and I look forward to hearing back from you.
Best regards,
Mario