Feature #11629: Implement Enhanced Mail System Status Codes (rfc1893)

• Status: Open
• Priority: Normal
• Assignee: -
• Target version: -

[rupert (Robert Pankowecki)]

Here is a list of exceptions raised by net/smtp.rb

      def exception_class
        case @status
        when /\A4/  then SMTPServerBusy
        when /\A50/ then SMTPSyntaxError
        when /\A53/ then SMTPAuthenticationError
        when /\A5/  then SMTPFatalError
        else             SMTPUnknownError
        end
      end

When the server responds with Net::SMTPServerBusy: 401 4.1.3 Bad recipient address syntax it raises SMTPServerBusy where it could use the enhanced information and throw a more specific error such as BadMailboxAddressSyntax based on what the RFC says:

       X.1.3   Bad destination mailbox address syntax

          The destination address was syntactically invalid.  This can
          apply to any field in the address.  This code is only useful
          for permanent failures.

Then it would be easier for the client to catch such specific exceptions and handle them properly instead of dealing with more general ones.