[imp] [patch] Configurable Received: header behavior

[Aleksandar Milivojevic]

Brian Keifer wrote:
> Hi, All.
> 
> I've been seeing some people mentioning that they have issues with spam filters
> seeing their dial-up or otherwise dynamic IP in the Received headers and
> thinking the messages are originating from a mail server in dynamic space.
> I've been bitten by this as well recently, so I wanted to do something about
> it, if only for my own server.

Hmm, such an MTA (or spam filter) would block hell lot of legitimate 
mail.  Basically, it would block each and every mail originating from 
dynamic-IP user, because every MTA at every ISP I know about would add 
Received header containing user's dynamic IP address.

My guess is that those sites are blocking emails that have Received 
headers containing "with HTTP", and do not particularry care about the 
IP address itself.  IMO, more usefull option would be to fake protocol 
in the Received header ("with SMTP", instead of "with HTTP").

Since "from host" and "with atom" parts of Received header are optional 
("by host", "id string", and "; date" are the only mandatory components 
of Received header as per RFC822), another option would be ommiting 
"with HTTP" (or optionally "from host"), instead of faking it.

Of course, this shouldn't be default behaviour (and should be marked as 
highly not-recommended), but maybe something administrator might turn 
on/off in case of crisis.

-- 
Aleksandar Milivojevic <amilivojevic at pbl.ca>    Pollard Banknote Limited
Systems Administrator                           1499 Buffalo Place
Tel: (204) 474-2323 ext 276                     Winnipeg, MB  R3T 1L7