I'm the mail administrator for an ISP that recently realized the
benefits of Exim over Qmail. I finally became tired of the lack of Qmail
updates and the wide array of 3rd party patches needed to give Qmail
even basic features.
We've also been using MailShield, a mail proxy that scans mail before it
reaches our servers. It filters based on a wide variety of things, most
importantly, message content. MailShield, too, is plagued with lack of
updates and support, but filters message content fast.
I discovered Exim has a built-in filtering mechanism, and after looking
through the Exim 4 Filtering FAQ, believe it can do everything we need
it to. We'd like to do user-level filtering, for customers who have
chosen to have their mail filtered.
However, we filter an ever-growing number of things. Over 4000 subjects,
2000 IP/blocks, and hundreds of message-body URL's. It would be
impractical to do this 4000 times:
if $header_subject matches "get.+rich.+quick"
then
finish
endif
How can we read a file containing a list of regexp values (subjects), to
match against $header_subject? For example, read a file into an array
and do:
if $header_subject matches @listofsubjects
Or, somehow do a regexp "lsearch" on the file. I realize we could,
instead of using Exim filters, write some perl to do this.. but we want
to stay within Exim as much as possible.
It's important to be regexp, because our subjects are optimized. For
example, we have "get rich quick" which catches "get rich and happier
quick".
Would performance be too much of an issue to do that in Exim? We have 3
load-balanced Sun Ultra 10's which handle 2000 messages/hour each, but
only 5% of that mail is filtered.
Thanks for any help, and I apologize for anything obvious I missed,
Rich
richs@???
WhidbeyNet Network Operations
