[Pkg-exim4-users] Spam sent to user from user's email address

[Boyd Stephen Smith Jr.]

In <4D2EB113.9050809 at didm.co.uk>, Peter Sparkes wrote:
>My Exim4 users are getting spam sent to them which appear to come from there
>own email address.
>
>Assuming that these emails are originating from my exim server how do I,
>please, stop them

The "From" header is effectively free-form.  It isn't used for routing the 
message to its destination, so it isn't something that is to be trusted.

SPF can make the "From" header part of bulk mail filtering; if your users will 
put up with it, a very restrictive SPF policy can reduce the amount of SPAM 
that has your domain in the "From" header.
-- 
Boyd Stephen Smith Jr.                   ,= ,-_-. =.
bss at iguanasuicide.net                   ((_/)o o(\_))
ICQ: 514984 YM/AIM: DaTwinkDaddy         `-'(. .)`-'
http://iguanasuicide.net/                    \_/
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