what method do you want to use to send email?
this is a basic method using cdo, which will work as is from many xpand some vista computers
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("a1")) Is Nothing And Range("a1") = 1 Then
cdo = CreateObject("cdo.message")
cdo.to = "firstname.lastname@example.org"
cdo.from = "email@example.com"
cdo.Subject = "cdo test"
cdo.textbody = "this is the content " & Range("b17").Value
for computers with no registered email client, you may need to set all the configuration properties, also it you want to use a gmail or similar account, again you will need to set the configuration properties