System.Net.Mail.SmtpStatusCode.MustIssueStartTlsFirst Field

The SMTP server is configured to accept only TLS connections, and the SMTP client is attempting to connect by using a non-TLS connection. The solution is for the user to set EnableSsl=true on the SMTP Client.

Syntax

SmtpStatusCode MustIssueStartTlsFirst

Requirements

Namespace: System.Net.Mail
Assembly: System (in System.dll)
Assembly Versions: 2.0.0.0, 4.0.0.0
Since: .NET 2.0