Подскажите, что делаю не так:
MailServer = "smtp.yandex.ru"
MailFrom = "MyMail@yandex.ru"
MailTo = "ToMail@mail.ru"
MailTheme = "Тест"
MailBody = "sss"
Login = "MyMail"
Pass = "MyPass"
Port = 465

NumErr = GetNumErr()
ErrParamStr = GetErrStr()
emailSender = New System.Net.Mail.SmtpClient(MailServer, Port)
emailSender.EnableSsl = True
emailSender.Credentials = New Net.NetworkCredential(Login, Pass)
emailSender.Timeout = 10000 '10 секунд
theMessage = New MailMessage
theMessage.From = New MailAddress(MailFrom)
theMessage.To.Add(MailTo)
theMessage.Subject = MailTheme
theMessage.Body = MailBody
emailSender.Send(theMessage)

Результат:System.Net.Mail.SmtpException: Время ожидания операции истекло.