I am trying to send bulk email to our database. I can get 85 out of the 800+ emails to send. after than I get this message. 

Failure sending mail. => Unable to read data from the transport connection: net_io_connectionclosed.

The exception log shows

   at System.Net.Mail.SmtpReplyReaderFactory.ProcessRead(Byte[] buffer, Int32 offset, Int32 read, Boolean readLine)

   at System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine)

   at System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller)

   at System.Net.Mail.CheckCommand.Send(SmtpConnection conn, String& response)

   at System.Net.Mail.MailCommand.Send(SmtpConnection conn, Byte[] command, MailAddress from, Boolean allowUnicode)

   at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception)

   at System.Net.Mail.SmtpClient.Send(MailMessage message)

Azure Server IIS7.... any thoughts?