Keep it short. Your son and his girl will be reading through a lot of notes and your message will get lost if you are not succinct. It's best to keep the note between three and five clearly written, original sentences.

Include both your son and his girl's name in the note. You want to make sure the note is personal and special to both your son and his girl, and the easiest and simplest way to accomplish this task is to include their names. Make sure to spell your son's fiancee's name correctly. Look at old correspondence you may have and, if all else fails, ask.

Express wishes for their future happiness. Giving your blessing as a father will mean everything to them. Even if you are unsure about your son's decision, it's his life and the day will go a lot smoother if you put ambivalent feelings aside and wish the couple a happy future together. You can say something like: "May each and every day be blessed with love and happiness."

Offer your support. Although a pleasant experience, getting married is also one of the most stressful times a couple can experience. Just knowing they can rely on you will alleviate stress. You can say something like: "Know that if you need anything, I am there for you."

Include a special memory you have of the couple. This sentiment will show how much you care and will be remembered with tenderness. You can say something like: "The first time I saw you two together, happiness radiated off both of you."

Write the note by hand and send it through the post office. An email crafted on a computer is impersonal and will not stand out as much as taking the time to write the words by hand and mailing the note personally.