Jerry Stuckle wrote:

> Mails should not be relayed. They should go directly from your MTA to
> the recipients MTA.
>
> Relays are an indication of an insecure system - typically used by
> spammers. But genuine MTA's don't use (or need) them.

Actually - thoroughly secured email systems make use of more than just
those two.

In large, well-secured, corporate email systems, mail often goes through
several relays that perform various security actions.

At Nortel, they relay through several Exchange servers on the way out
of, and into, the network. At GTE, they relay(ed) through a wildly
complex Banyan Vines system.

It's sometimes quite interesting to check out the headers on various
corporate emails because they go through SO MUCH e-bureaucracy.