Sample
[DATE, ex. Friday, February 10, 2006]
[NAME, COMPANY AND ADDRESS, ex.
Robert Brown
XYZ Inc.
1234 First Street
Suite 567
Anycity, Anystate 85245]
Dear [NAME, ex. Robert Brown],
ICongratulations! I just heard the wonderful news.
I respect and admire your choice of partner and I have no doubt that the two of you will compliment one another.
I wish you all the best in the years to come.
Best regards,
[YOUR NAME]
PS. You know who to call if you ever need any "words of wisdom".