Re: [Exim] Whitelisting in Exim?

Hi Robison, on Sat, 10 Jan 2004 18:08:40 -0800 you wrote:

> ipowerweb implemented new security patches on their server end.
> They are now using Exim to block (not merely tag) mail according to
> the SpamCop database.

Then they are, to be honest, slightly silly. Blocking outright on SpamCop
is pretty much guaranteed to block a not-insignificant amount of "real"
e-mail.

> Can anyone send me detailed instructions I can pass on to
> ipowerweb's technical support as to how they can configure their Exim to
> whitelist nstarsolutions.com, or even how to quit filtering all mail
> headed for me?

As someone pointed out, they seem to be using Exim 3 (very ancient and
unsupported, and much less flexible than Exim 4, which is what pretty much
all of us use). This seriously limits their options; I can't recall if
there's anything they can do to exempt certain domains/recipients from
DNSBL checks.

If I were you, I would tell them:

a) stop being silly and stop blocking based on SpamCop. Sure, using
sbl-xbl.spamhaus.org, list.dsbl.org, relays.ordb.org etc. is probably OK,
but SpamCop is not really suitable as an out-and-out reject list.

b) if they are going to implement extremely aggressive spam blocking, they
should first upgrade to Exim 4 so they have more flexibility, and make the
more aggressive blocking "opt in" for customers. In fact, they should
upgrade anyway, not least to gain the power of Exim 4 which will let them
do all kinds of extra spam-blocking tricks which, coupled with the above
lists, will probably block enough spam to avoid the need to resort to
extremely aggressive block lists.


This example does illustrate the nightmares caused by spammers though.
From the point of view of people running mailservers, to a certain extent
we're damned if we do and damned if we don't, given that 100% accuracy in
blocking spam is impossible. However, your ISP in this case are certainly
not doing themselves any favours by outright blocking on SpamCop and
without (and before) giving themselves the flexibility and power of Exim
4.


Tim