Send italian PEC with ASP.NET

Dim myMail As New MailMessage()
Dim fromEmail As String = "emailpec"
Dim toEmail As String = "emailpec"
Dim mySmtp As New SmtpClient("smtppec")

mySmtp.UseDefaultCredentials = False
System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12
mySmtp.Port = 465
mySmtp.EnableSsl = True
mySmtp.Credentials = New System.Net.NetworkCredential(fromEmail, "PASSWORD")

myMail.From = New MailAddress(fromEmail)
myMail.To.Add(toEmail)

myMail.Subject = "test send pec"

myMail.IsBodyHtml = True

myMail.Body = "test send PEC"

mySmtp.Send(myMail)