log4net:ERROR [SmtpAppender] ErrorCode: GenericFailure. Error occurred while sending e-mail notification.

Error happens when trying to send emails.

I have checked github source here to try help with this problem.
https://github.com/apache/log4net/blob/782e8267dc44a3db5e0b095c91c1de76a37a9e9b/src/log4net/Appender/SmtpAppender.cs

If you wrap the SmtpClient (on Line 394 ) It should probably fix this issue. Thats just from my experience. Please let me know if you need anthing else?

Please see the error log from my debug console.

log4net:ERROR [SmtpAppender] ErrorCode: GenericFailure. Error occurred while sending e-mail notification.
System.Net.Mail.SmtpException: Failure sending mail. ---> System.IO.IOException: Unable to read data from the transport connection: net_io_connectionclosed.
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)
— End of inner exception stack trace —
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at log4net.Appender.SmtpAppender.SendEmail(String messageBody)
at log4net.Appender.SmtpAppender.SendBuffer(LoggingEvent[] events)