Local domain not recognised

[Stephen Davies]

I am seeing log messages like:

Open relay? Nonlocal recips but not originating: john at agua.com.au


Agua.com.au is one of my three domains (all with the same IP address) 
and is listed in local_domains_maps.

Why is the above address not recognised as local?

The warning is raised regardless of whether the email is sent internally 
or from an external source.

Cheers,

Stephen