Can anyone tell me what this error means and what causes it?
Log type: MailError
Severity: 11
Message: Error sending e-mail. Transaction failed. The server response was: mail server permanently rejected message (#5.3.0)
Exception: System.Net.Mail.SmtpException: Transaction failed. The server response was: mail server permanently rejected message (#5.3.0) at System.Net.Mail.DataStopCommand.CheckResponse(SmtpStatusCode statusCode, String serverResponse) at System.Net.Mail.DataStopCommand.Send(SmtpConnection conn) at System.Net.Mail.SmtpConnection.OnClose(Object sender, EventArgs args) at System.Net.ClosableStream.Close() at System.Net.Mail.MailWriter.Close() at System.Net.Mail.SmtpClient.Send(MailMessage message) at NopSolutions.NopCommerce.BusinessLogic.Messages.MessageManager.SendEmail(String Subject, String Body, MailAddress From, MailAddress To, List`1 bcc, List`1 cc) at NopSolutions.NopCommerce.BusinessLogic.Messages.SendQueuedMessagesTask.Execute(XmlNode node)
Thanks