Re: Received header and fake hello name

[Bill Cole]

On 17 Jul 2012, at 13:12, LittleCho wrote:

Okay, it seems the postfix should place any hello name there even it 
is faked according to RFC 5321. Thanks for your reply.

Yes, and there's a good reason for that. The HELO parameter is an 
identity that the sending system knows for itself. In cases where 
multiple systems are subjected to NAT gateways that put their traffic on 
one external IP address, the HELO can be useful in identifying which one 
of the systems sharing the NAT handled the transaction.