Mark Constable writes:

> The point I was making about the postfix configuration is that it works
> when the SPF/TXT record for the domain only includes the IP of the domain
> on the virtual interface without having to include the default eth0 IP as
> well. This is the "magic" I was hoping courier could also emulate. Ie;...
>
> 206.221.219.125- unix - n n - - smtp
>  -o smtp_bind_address=206.221.219.125
>
> So is the bottom line there is no way for courier to provide a binding to
> the virtual interface so that it would pass SPF checks without having to
> add the default eth0 IP of 206.221.219.122 to the SPF record for eth-os.org?

If you're looking to have /all/ outgoing mail sent from a socket that's  
bound to that IP address, this would be the SOURCE_ADDRESS (or  
SOURCE_ADDRESS_IPV6) setting in the courierd configuration file.

I'm not familiar with Postfix config setting, but I didn't see anything  
there that's domain specific, so I'm assuming that all it does is set the IP  
address for outgoing sockets, for all mail. That's the SOURCE_ADDRESS  
setting.