[CentOS] SPAM on the List

Always Learning centos at u6.u22.net
Mon Jul 18 03:26:27 UTC 2011

On Sun, 2011-07-17 at 22:12 -0500, Les Mikesell wrote:

> On 7/17/11 9:37 PM, Stephen Harris wrote:

> > (RFC821 actually wanted the HELO to match the connecting host, but
> > 2821 just says it must be an A record or an address literal).

> That's a long way for saying it MUST be the name of that particular host (which 
> might be one of many in a cluster sharing a name) or that it MUST use the name 
> of the interface that it happens to use for a particular connection, or that its 
> own interface IP MUST be what connects to the target with no NAT involved. 
> Saying any of those things would make it very difficult for mail services to scale.

Sorry if I seem thick but I am having problems understanding why, with
the use of NAT, the HELO/EHLO and their external IP address can not
match.  Also what influences does scaling have on the ability of sending
mail servers (MTAs) to operate with host names that match their IP
addresses ?


With best regards,


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