Imports System.Text.RegularExpressions

Public Class Form1
 Public Function IsValidEmail(ByVal email As String) As Boolean
  Dim pattern As String = "^[-a-zA-Z0-9][-.a-zA-Z0-9]*@[-.a-zA-Z0-9]+(\.[-.a-zA-Z0-9]+)*\." & _
  "(com|edu|info|gov|int|mil|net|org|biz|name|museum|coop|ru|aero|pro|tv|[a-zA-Z]{2})$"
  Dim check As New Regex(pattern, RegexOptions.IgnorePatternWhitespace)
  Dim valid As Boolean = False
  If String.IsNullOrEmpty(email) Then
   valid = False
  Else
   valid = check.IsMatch(email)
  End If
  'return the value to the calling method
  Return valid
 End Function
End Class