[77770] in North American Network Operators' Group
Re: Time to check the rate limits on your mail servers
daemon@ATHENA.MIT.EDU (Sam Hayes Merritt, III)
Fri Feb 4 11:49:07 2005
Date: Fri, 4 Feb 2005 10:46:04 -0600 (CST)
From: "Sam Hayes Merritt, III" <sam@themerritts.org>
To: Michael Loftis <mloftis@wgops.com>
Cc: nanog@merit.edu
In-Reply-To: <ACDDC769D7AA6CFF59426ECF@d216-220-25-60.dynip.modwest.com>
Errors-To: owner-nanog-outgoing@merit.edu
On Thu, 3 Feb 2005, Michael Loftis wrote:
> --On Thursday, February 03, 2005 11:42 +0000 Michael.Dillon@radianz.com
> wrote:
>
>> Do you let your customers send an unlimited number of
>> emails per day? Per hour? Per minute? If so, then why?
>
> Because there are *NO* packages available that offer limiting. Free or
> commercial.
I disagree.
On a per IP basis, sendmail now offers
ClientRate, number of connections allowed within a 60 second sliding
window from a given IP
and
ClientConn, number of active connections allowed from an IP at any time
Used in conjunction with Jochen Bern's bm patch available from
http://www.informatik.uni-trier.de/~bern/sendmail/ which limits the number
of mail commands given in a single connection, you can rate limit your
users fairly well. We have used these limits for ~6 months now and have
only had to whitelist 3 sites from the Client limits.
You could probably adjust the window size for the ClientRate and then
limit the number of smtp commands per connection to achieve like an hourly
limit of some sort.
sam
