Thanks for the article I found it very interesting. This is what I use as a cover letter.

Dear

I am submitting my story title for your consideration.

My name is Sam H Arnold and I am a freelance author and book reviewer. I have written three novels and write for various online publications both fiction and non-fiction. One of the publications I regularly publish for is Kent Teach. Working for this company allows me to combine my two professions, writing and teaching.

I have been publishing for over 3 years now and have a following of over 2000 across all social media. I hope you enjoy my work.

Thank you for your time.