Check if email server is alive

SmtpAlive.vb

Imports System.Net.Sockets
Public Function SmtpAlive(ByVal hostName As String, ByVal port As Integer)
        Using tcp As New TcpClient
            Try
                tcp.Connect(hostName, port)
                Return True
            Catch ex As Exception
                ' server not found
                Return False
            End Try
            tcp.Close()
        End Using
    End Function