Dear Employer,
This is my first time working with freelancer, most of the time I been working for companies in a long-term relation.
I am very interested in your project because on the one hand, I have a lot of experience with PHP, I will be able to change the content of your website easily. On the other hand I been working with SEO so I know which tags should I use and how to build a website in the best way so search engines will index it.
If at the end of the work you are satisfied with my work I would like to keep in touch with you for further maintenance of your projects