- In the opening paragraph, briefly introduce yourself and state the purpose of the letter. We'll detail everything you need to know about how to invite a guest speaker, from the earliest planning stages to drafting a formal speaker invitation letter.On behalf of the XYZ and the XYZ Organizing Committee, we are honored to invite you to speak at the XYZ event celebrating Cybersecurity Career Week (CCW). I am writing to ask whether you would be willing to present a talk at the conference as an invited speaker. Invited talks will be one hour long. The following dinner invitation examples cover everything from a casual dinner party to gala dinner invitation wording. The letter is an invitation from Sogod National High School to three teachers from different schools to be recollection speakers for their graduating students. Your invitation should be a formal email (or letter). Outline the reasons why you've chosen them as the best person to speak at your event. Your invitation should be a formal email (or letter).