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],
It was a pleasure to see your new [office / manufacturing plant / etc.] the other day and to take a tour around the premises. I am certain that it will be a source of prosperity and enjoyment for you.
Allow me, then, the opportunity to compliment and congratulate you on your new [office / manufacturing plant / etc.] and to wish you the best in the future.
Best regards,
[YOUR NAME]