+++ Matthew Byng-Maddick [exim-users] <16/02/02 00:32 +0000>:
> > A far better solution is to open a socket to localhost:25 instead of calling
> > exim with -t -oi -oem -f or whatever.
> This is never a good solution. What have you done with the real Suresh?
I'm the real guy ...
> This is only a solution if you are prepared to queue mail before it gets
> to the local SMTP port. The correct solution is that you call
> /usr/{sbin,lib}/sendmail -oi -oem -bm -f <sender> <recipient> <recipient...>
> and pipe it the message on standard input.
I was actually thinking of the Mail::Mailer module or similar for this.
> This is *ALWAYS* the correct solution for local delivery.
Local submission actually ... for delivery elsewhere. This also helps in
situations like what we are looking at for our webservers (running webmail
for some very high traffic sites).
There's one centralized (and heavily filtered) smtp server [either sendmail
8.12 or exim - happen we can get the DCC <
http://www.rhyolite.com/dcc/>
working on exim] - the webservers run qmail configured as a nullclient
smarthosting through the central smtp server.
This (partly) deals with a problem we - and several other webmail providers -
have been facing. Idiots operating from several hundred open proxies,
running bots against webmail servers to
[1] create an address
[2] spam through it (keeping just below our restrictive rate limits)
[3] switch to new proxy
[4] goto [1]
Yes, that *is* an endless loop ...
The other thing we do to open proxies we see (or those listed in the dnsbl at
http://www.blitzed.org/opm/ ..) is to block them from our mailservers and
webservers. [mailservers - using rbldns <cr.yp.to/djbdns/rbldns.html>.
webservers, we use squid ACLs, as we use squid as a http accelerator.
another way to go would be to use the apache mod_access_rbl module available
at blars.org)
This should also deal with the problem most webhosts face - idiots signing up
for an el-cheapo webhosting account which offers cgi-bin (and shell access to
boot), uploading spamware perl scripts + the contents of a spamware CD, and
spamming out the wazoo, with the envelope sender set to stuff like
nobody@???
Or the other ever-present problem - spammers exploiting formmail.pl or
similar insecure perl scripts.
-srs
