Any Way to Plug This Hole in Local Sendmail Delivery?

[Jeffrey Goldberg]

On Apr 5, 2007, at 8:14 PM, RW wrote:

> On Thu, 5 Apr 2007 13:18:33 -0500
> Jeffrey Goldberg <jeffrey at goldmark.org> wrote:
>
>> The second is that the spammer could be forging in the sender
>> address (envelope FROM)
>>
>>    MAIL FROM:<user at your.domain>
>>
>> The third type of forgery is in the header From address.
>
> Bear in mind that both of these are often done legitimately; for
> example by people working from home and using their ISP's server to
> send an email to a colleague.

Yes.  If you set up something like this it is important to provide an  
SMTP submission service.  This allows your off-site users to use your  
mail server by authenticating with it.

-j