I hope this message finds you well! I'm reaching out today with an exciting speaking opportunity for your consideration.Here is a sample agenda for guest speakers: Welcome and Introduction (5 minutes); Presentation (30 – 40 minutes); Questions from the Audience (remaining time). State the occasion, date, time, and place. Present your credentials, explain how your expertise aligns with the conference theme, and express your enthusiasm for contributing. I am writing this letter to inform you about the upcoming__( mention the occasion or the event) It has been a while since we all have met up. 1 Formatting the Letter. Format the invitation as you would a formal business letter.