I have a table that contains a field for birthdate.
I would like to notified whenever it is someones birthday via e-mail
Any suggestions

A partial solution. Here's how you'd identify someone in your table whose birthday is today (using US short-date format):

SELECT LastName, FirstName, DOB, DatePart("yyyy",Date())-DatePart("yyyy",[DOB]) AS age
FROM tblClients
WHERE (((DatePart("m",[DOB])=DatePart("m",Date()) And DatePart("d",[DOB])=DatePart("d",Date()))=True));