Dear [agent], (good)
Max is convicted (passive) for murder and sentenced (split-conjunctive passive verb) to serve the Crown with his memories removed by (passive) magic. (Three passive passes in the first sentence spells instant rejection for most agents. The telling overkills... and this in your hook. Revise.) While serving his time (Hidden and telling gerund phrase), he uncovers his past (telling), (incorrect punctuation) the details of (wordy) his crime and why the memories were taken (passive) (sounds too bizarre, telling, and disconnected). Then (if you use then to start a sentence, a comma must follow - missing punctuation) he must (hedging modifier - consider a stronger word or rephrase the word decide) decide between his new life and the old (incorrect sentence structure - the 'and' makes the last phrase reads like this: his the old. Also, it sounds cliché).
TALES OF EASTMARCH is a ##,000-word fantasy novel, (correct comma use, but not needed) similar to Ed Greenwood's The Kingless Land. (And? Nothing else?)
I'm a finalist in the Wordclay Short Story Contest of 2008 and wrote two short stories in the anthology The Orpheus Tales from Salvatore Publishing in 2008. (excellent) (I would like to see something more here. If not, separate the sentences to make the credits look longer.)
Thank you for your time. (good)
Sincerely, (excellent)
Watch the passive voice. You don't want to stumble in the first sentence. Hell, you don't want to stumble at all. Revise and consider the conflict further. Again, I would like to see a theme and so do agents.
Wolfe