[Greylist-users] Possible Enhancements

[Steven Grimm]

Deke Clinger wrote:

>This technique assumes that the MX for a given domain (the inbound mail
>handler) is also always the outbound mail handler. This is almost never true
>for domains of significant size and it's becoming less and less true for
>smaller sites, what with hosted mail service, etc.
>
>There's a lot of work afoot to define and publish 'designated sender' records
>in DNS (RMX, SPF, caller-id, etc) but it's not sound to assume that mail for a
>given domain will come _from_ the machines in the MX record.
>  
>
At which point you greylist and are no worse off than before.

(Again, I don't think this is a good idea, but that's not why it's bad.)

-Steve