Correção: "Unfortunately, I cannot set a date..."

The statement is: "One of your new clients contacted you by email, and has asked if you are available for a meeting on Wednesday. Write your response below."

Dear Sir Tom.

Unfortunately, I cannot set a date on the next Wednesday once I have already set other meetings for this day. I will email you as soon as possible and by the end of this email you will be able to comprehend the main guidelines of our company and its principles.

Yours sincerely, Giovana Martins.

I'd like to know if I made any mistakes or if I can improve my passage in some way.