[NAME, COMPANY AND ADDRESS, ex.
Jill Smith
XYZ Inc.
1234 First Street
Suite 567
Anycity, Anystate  85245]
 

Dear [NAME, ex. John Smith], 

Well the time has finally come!

I'm very happy for you and [NAME OF SPOUSE, ie. Jack] and I wish you both and the newborn the very best. 

You did a great job in organizing your workload and delegating it to others during your absence, and we'll all pull together to make sure things get done.

{Please let me know when the moment gets closer so I'll have the inside track on the baby pool!} 

Take care and see you soon.
 

Best regards,

[YOUR NAME, ex. John Jones]