Re: Question about Qmail relating to MX retry processing

[Marc Perkel <marc@perkel.com>]

Ron Guerin wrote:

Marc Perkel wrote:
  

Uncle George wrote:
    

Well, not exactly from an RFC, but from
http://en.wikipedia.org/wiki/MX_record

      

The sending agent then attempts to establish an SMTP
<http://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol>
connection to one of these servers, starting with the one with the
smallest preference number, delivering the message to the first
server with which a connection can be made.
        

I guess the operative word would be *connection*.  The SMTP dialog
appears to have established a connetion.

But if you read on to the next paragraph of the WIKI, one senses that
they dont mean connection, but rather the acceptance of the e-mail.
Which appears to be your position.
      

Suppose your mail server relies on an NFS mount and suppose the NFS
server is down. The server might connect but in the process of receiving
the email the server fails because it can't write to something it needs
to write to. So it returns a 4xx error. The is a backup server on a
higher MX that is there to accept email in case something like this
happens. But Qmail won't send the email to the backup MX?

There's a spec - everyone else follows the spec - except qmail.
    

You're beating a dead horse.  The best you're going to get here is an
argument about what the RFC requires.  You're not going to get every
qmail site to patch their system.  So the bottom line is, you've got to
say goodbye to this particular technique you're using.

- Ron

  

I'm not sure that's the case. It just means the those who use qmail AND (have bad reverse lookup OR are on a dynamic IP address) will not be able to send email to my domains UNLESS I whitelist their host.