Validate email with Regxp (regular expression) in Visual Basic 6.0

option explicit
private Function IsValidEmail(ByVal emailStr As String) As Boolean
   
    ' if email is blank then return
    If VBA.Len(VBA.Trim$(emailStr)) = 0 Then
        IsValidEmail = False
        Exit Function
    End If
  
   
    Dim regex  As  Object
    Dim cMatch  As  Object ' For MatchCollection

    Set regex = CreateObject("VBScript.RegExp")  ' Object created with VBscript.RegExp class.

    regex.MultiLine = False ' email is a single line expression therefore multiline is set to false

    regex.IgnoreCase = False  ' Case sensitive checking is set to true

    regex.Pattern = "\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b" ' regular expression pattern

    Set cMatch = regex.Execute(emailStr)
   
    IsValidEmail = Not (cMatch.Count = 0) ' If no matches found then email is invalid

    ' first item of  collection cMatch return length of the email is it is not equal to the length of meail email is invalid.
    If IsValidEmail Then IsValidEmail = IIf(VBA.Len(cMatch.Item(0)) = VBA.Len(emailStr), True, False)
    'Release memory
    Set cMatch = Nothing
    Set regex = Nothing
End Function

Private sub Form_Load()
    if not IsValidEmail("subhroneelganguly@gmail.com")  then
        msgbox "Email not valid"
   else
      msgbox "Email valid"
    end if
End Sub