Writing to exchange contactitem fails

I'm updating exchange server from an access database using
outlook.application. It all runs just fine until I reach writing to the
email-fields. I can't set Email1Adress to a simple string. I get the error
"Object doesn't support this property or method"

MyItem.FullName = rstNavAfd!KassererNavn & " " &
rstNavAfd!KassererNavn2
MyItem.JobTitle = "Kasserer"
varLook = DLookup("E_mail", "navDebitor", "Nummer = '" &
rstNavAfd!KassererNummer & "'")
If (Not IsNull(varLook)) And varLook <> "" Then
MyItem.Email1Adress = varLook ' Here it goes
wrong !!!!
End If

Can anybody help?
regards
Jakob