Thanks Chris.
Can you please suggest some documentation on running a second daemon only
for outgoing messages?
We have squirrelmail for receiving mails from local users. Is it possible to
ratelimit mails in this environment?
Regards,
Biju.
-----Original Message-----
From: Chris Siebenmann [
mailto:cks@cs.toronto.edu]
Sent: 31 October 2014 AM 10:04
To: Biju Abraham N.
Cc: exim-users@???; cks@???
Subject: Re: [exim] Exim4 ratelimiting
> I am trying to ratelimit outgoing messages in my exim4 daemon. Many a
> times, our mail server has been hacked, multiple identity has been
> added and using those ids, hackers send out bulk spam mails. Once the
> limit is overcome, many domains are blacklisting us. As I understand
> from the manuals and searching the mailing lists, outgoing mails can
> not be ratelimited. Please correct me if I am wrong.
One hacky way around this is to run a second daemon in some way (there are
a bunch of ways; another (virtual) machine is the easy one). Route outgoing
messages to the second daemon via SMTP and then have that daemon ratelimit
how many incoming messages it accepts from your main daemon.
If users submit outgoing mail to your daemon using SMTP, you can also
obviously ratelimit their incoming sending attempts. I don't think that this
works if users submit mail by directly running commands on the same machine
as the mailer, though, and it sounds like this may be your problem.
- cks
