Error:
System.Net.Mail.SmtpException: Mailbox unavailable. The server response was: 5.7.1 Message rejected as spam by Content Filtering.
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 Nop.Services.Messages.EmailSender.SendEmail(EmailAccount emailAccount, String subject, String body, String fromAddress, String fromName, String toAddress, String toName, String replyTo, String replyToName, IEnumerable`1 bcc, IEnumerable`1 cc, String attachmentFilePath, String attachmentFileName, Int32 attachedDownloadId, IDictionary`2 headers) in C:\XXXX\nop-4.10\src\Libraries\Nop.Services\Messages\EmailSender.cs:line 153
at Nop.Plugin.Misc.SendInBlue.Services.SendInBlueEmailSender.SendEmail(EmailAccount emailAccount, String subject, String body, String fromAddress, String fromName, String toAddress, String toName, String replyTo, String replyToName, IEnumerable`1 bcc, IEnumerable`1 cc, String attachmentFilePath, String attachmentFileName, Int32 attachedDownloadId, IDictionary`2 headers)
at Nop.Services.Messages.QueuedMessagesSendTask.Execute() in C:\XXXX\src\Libraries\Nop.Services\Messages\QueuedMessagesSendTask.cs:line 69
Any idea how to fix it?