I am writing to you regarding my completed novel, The Legacy of about 101,000 words. The story is a historical fantasy based on Greek mythology. The Moirai [Who are these Moirai - a tribe? A race? Elf-like creatures hiding in Herodotus' robe?] foresee a future where the Olympian Gods will fade from immortal existence and are replaced by a single entity [watch the grammar - you mixed future and present tenses]. To prevent this from happening, the sacred relics of the Mother Goddess, whose power is supreme, must be restored [restored to where - a temple? A town?] to avert the extinguishing power of the gods [watch the grammar here]. Poseidon's children, the Atlanteans, have been chosen to seek out the relics or face extinction.
My target audience would be readers of George R.R. Martin and Kate Mosse [whoa there, cowboy - you haven't convinced me to read your story yet, so it's a bit early to tell me whose readers you think would like it], although my story differs from the traditional telling of historical novels. My story draws on ancient history and mythology to tell a provocative yet epic tale of intrigue, betrayal, a loss of belief and the everlasting impact it has on the characters. [This is a good sentence - move it up to the first paragraph so it comes after the sentence ending 'Greek mythology' and then start a new para to tell me about the story itself.] This is my first work of fiction which is part of a series, the second book is completed and I have begun writing the third.
I'm Australian and live in Perth, city of Western Australia. I have studied Ancient History [this is an example of pertinent detail - if you're writing about Ancient Greece, I do want to read that you've studied Ancient History], completed a series of writer's workshops at the University of Western Australia and concluded a Proofreading course. I am an affiliate member of the Australian Society of Authors and member of The Katharine Susannah Pritchard's Writers Centre. [All good information.]
Please find attached a synopsis and a sample of my manuscript The Legacy. I have included my e-mail address for a reply. If the manuscript is to your liking, I'd love to send you a larger sample or the entire manuscript.
I look forward to hearing from you.
Overall feedback: You buried the best sentence of your pitch deep in the second paragraph. If you move it up to the first para, you'll see how it will change what detail you want to include after it, because the story you described in the first para didn't seem provocative, or that it contained intrigue, betrayal or a loss of belief. So either that really good sentence doesn't represent your story, or you haven't described the story in a way that fits with the pitch.