SMTP Error: Server does not support secure connections Rasmus Jensen June 25, 2019 09:09 ReasonSMTP is not configured to run TLS SolutionUncheck TLS option in SMTP Settings or use an SMTP that support TLS Related articles SMTP Error: 5.7.57 SMTP / Client was not authenticated to send anonymous mail SMTP Error: Failure sending mail SMTP Error: System.Net.Mail.SmtpException (General) Outlook Error: HRESULT: 0x80004002 (E_NOINTERFACE) SMTP Error: Open relay not allowed