On 20 May 99, at 12:10, Debra Wilson wrote:

>
> I thought that mail relaying is the act of sending an e-mail message by way of
> an organization that has nothing to do with either the sender or the recipient,

No. Mail relaying is simply the act of using one server to send mail to
another server. In certain cases, it is done illicitly, but in most cases
where you run into that error, it is quite valid relaying except that the
mail admin of the relaying machine made a mistake.

Generally, an organization will set up an "MX" record in their DNS, which
defines which servers may be used for relaying mail for that address. For
example, if you look at the MX records for HOTMAIL.COM, you see:

    mail3.HOTMAIL.COM 10 216.32.182.252
    mail2.HOTMAIL.COM 10 209.185.130.252
    mail.HOTMAIL.COM 10 209.1.112.253

This means that all mail to HOTMAIL.COM is relayed through one of those 3
servers. If the mail admin at HOTMAIL.COM forgot to tell mail2.hotmail.com
that it has to accept mail for HOTMAIL.COM (as opposed to
MAIL2.HOTMAIL.COM), then you'll get that error for every piece of mail
that goes through mail2.hotmail.com. However if mail3 and mail are
correctly configured, then mail that happens to go through those servers
will get relayed correctly. So under these circumstances, 2/3 of the mail
for HOTMAIL addresses will get through, and 1/3 will bounce with "Relaying
not permitted".

(Note: to my knowledge, this has never happened at HOTMAIL.COM, I just
used that as an example)

Francoise