Milter-greylist

Michael Mansour wrote:
> Hi,
> 
> I've whitelisted the following domain:
> 
> au.pwc.com
> 
> with the following in the greylist.conf file:
> 
> acl whitelist domain au.pwc.com
> 
> as they're valid senders to one of my clients.
> 
> However greylisting still delays emails coming from them and doesn't whitelist
> them. So I'm wondering, does the milter-greylist whitelist use the "from"
> domain or the domain of the smtp server?

That depends.. if you specify:

acl whitelist rcpt

You use the "from" domain, as seen by the message envelope (ie: MAIL FROM: 
command, which may not match the From: header in the message text, particularly 
for things like mailing lists.).

If you specify:

acl whitelist domain

Then you use the domain of the SMTP server.


This is all documented in man greylist.conf:

-------------
        domain This clause selects source machines based  on  their  DNS  name,
               performing  a  suffix search.  For instance, this will whitelist
               any machine in the example.net domain:
-------------

and:
-------------
        from   This  is  used to select sender e-mail addresses. You should not
               use that feature, because sender e-mail addresses can  be  triv-
               ially forged.  Example:
--------------

Although I would argue it is perfectly reasonable to use from for some things, 
but you can't trust it so only use it for whitelists as a last resort. (ie: 
forcing a blacklist or a longer-duration greylist based on from is perfectly 
reasonable.)