Dropping BCC

Hi,

Is it possible to configure exim to either drop emails using BCC or,
strip out the BCC header and replace with an empty BCC: header.

We've just had an issue where someone circumvented our input filtering
on a script and generated a lot of spam emails (all addresses were
added to BCC). We caught it relatively quickly, but, it was just by
chance I was on the server at the time. We've now patched this hole,
but, it's like plugging a leaking boat.

We only ever send automated emails out from this box, it's not handling
any incomming emails, we know that any emails which are addressed with
a BCC, or, even multiple recipients are bogus and should be dropped.

I know strictly speaking this isn't down to the MTA, but, when we're
dealing with spam, any port in a storm.

Thanks

Andrew

On 2007-03-12, Andrew Taylor <Andrew> wrote:
> Hi,
>
> Is it possible to configure exim to either drop emails using BCC or,
> strip out the BCC header and replace with an empty BCC: header.

[snip]

This is probably not precisely what you want, but I've just implemented it
so I'm throwing it out there anyway. :)

I use one single Exim config file on my Debian server, and I wanted to
remove some clutter from the headers of some mails I receive. This works for
outgoing mails too AFAIK.

In /etc/exim4/exim4.conf.template (I put this at the top) :

system_filter = /etc/mail/exim.filter


In /etc/mail/exim.filter :

# Exim filter

headers remove "Disposition-Notification-To"
headers remove "Return-Receipt-To"
headers remove "X-MSMail-Priority"
headers remove "X-Priority"
....
....


Then :

/etc/init.d/exim4 restart



The filter file *must* start with the hash and 'Exim filter' as shown AFAIK.

Maybe you could use this to remove BCC: headers ?

Regards,

BH.