判斷字符串是否是合法的EMail

Public Function IsValidEmail(strEmail As String) As Boolean
     Dim names, name, i, c
     IsValidEmail = True
     names = Split(strEmail, "@")
     If UBound(names) <> 1 Then
     IsValidEmail = False
     Exit Function
     End If
     For Each name In names
     If Len(name) <= 0 Then
     IsValidEmail = False
     Exit Function
     End If
     For i = 1 To Len(name)
     c = LCase(Mid(name, i, 1))
     If InStr("abcdefghijklmnopqrstuvwxyz_-.", c) <= 0 And Not IsNumeric(c) Then
     IsValidEmail = False
     Exit Function
     End If
     Next
     If Left(name, 1) = "." Or Right(name, 1) = "." Then
     IsValidEmail = False
     Exit Function
     End If
     Next
     If InStr(names(1), ".") <= 0 Then
     IsValidEmail = False
     Exit Function
     End If
     i = Len(names(1)) - InStrRev(names(1), ".")
     If i <> 2 And i <> 3 Then
     IsValidEmail = False
     Exit Function
     End If
     If InStr(strEmail, "..") > 0 Then
     IsValidEmail = False
     Exit Function
     End If
    End Function