out of place mx records.

[Tony Finch]

On Fri, 29 Oct 2010, Mark Andrews wrote:
>
> It would be nice if we could standardise a MX target of "." as saying
> that this domain doesn't accept email e.g. "MX 0 ." the same way as "SRV
> 0 0 0 ." means that there is no service for the named protocol.  That
> way the sending MTA or the MSA can reject the email.

Yup. Many MTAs already implement this.

> Every time it get suggested people shoot it down worrying about
> private nets that have addresses at "." or get worried about thousands
> of machines making A/AAAA queries for "." where the MTA doesn't
> check that the MX target is a valid host name.

Sigh.

Tony.
-- 
f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/
HUMBER THAMES DOVER WIGHT PORTLAND: NORTH BACKING WEST OR NORTHWEST, 5 TO 7,
DECREASING 4 OR 5, OCCASIONALLY 6 LATER IN HUMBER AND THAMES. MODERATE OR
ROUGH. RAIN THEN FAIR. GOOD.