Rate limiting qmail-send

Spooky Ghost · Posted: Fri Jan 04, 2008 5:50 pm Post subject: Rate limiting qmail-send

Hi,

Does anyone have a method of rate limiting qmail-send? I run a couple of low volume mailing lists using ezmlm from my home machine but there are approx 100 people on the lists. Because other people configure their mail servers to refuse connections or just drop messages from "dialup" DHCP addresses I have configured smtproutes so that all the traffic is routed via my ISP's SMTP servers. However, if there are more than ~30 messages a minute they think your machine is a spambot and you get letters telling you to visit microsoft.com and download the latest patches lol. Although they haven't got nasty yet this is against the Ts&Cs so I would like to resolve it. Basically I just want to restrict the number of messages that qmail-send will attempt to send in any one minute period.

Thanks,

PBR · n00b Joined: 02 Apr 2006 Posts: 13

IMHO Qmail does not have a way to do this. The way u can solve your problem is to write script and call it from the QMAILQUEUE mechanism. You can also install qmail-spp and write plugin to do the job for U.

Spooky Ghost · Posted: Wed Jan 09, 2008 10:10 am Post subject:

I don't think either of these methods (i'm not familiar with qmail-ssp but just having a quick read) would work as they operate on the inbound side of the mail queue. My understanding of ezmlm is that it submits just one message but uses multiple RCPT headers to target all the list subscribers. Since the message is handled by qmail internally this is why I need to be able to manage the outbound rate. The other option I can think of is to use a second mta installation locally as a relay and apply the limiting as initially suggested. I would be open to using an alternative to qmail for this if there are any systems which have such a feature out of the box?

manaka · Apprentice Joined: 23 Jul 2007 Posts: 178 Location: Spain

qmail is designed to be simple, secure and efficient :-)

. It doesn't implement all the features of the more bloated MTAs.

Postfix doesn't seem to implement this feature either (http://www.postfix.org/rate.html).

I would suggest trying kernel bandwidth limiting as the cleanest solution.
_________________
Javier Miqueleiz

"Listen to your heart. It knows all things, because it came from the Soul of the World, and it will one day return there."

Spooky Ghost · Posted: Thu Jan 10, 2008 9:14 am Post subject:

Bandwidth limiting doesn't restrict the number of messages, only the rate at which data is transferred. The aim is to only pass n messages / minute to the relay, not n bytes of data. Although you could perhaps try and restrict the number of TCP connections that are established / minute you could still have multiple messages delivered in the same session and therefore exceed the limit.

It seems that there is no feature of qmail that implements my requirement so I think that using an intermediate local relay is the only option. Looking into this further I think postfix can do what I need with a suitable anvil configuration.

manaka · Apprentice Joined: 23 Jul 2007 Posts: 178 Location: Spain

Yes, that's true... But let's see...

AFAIK, qmail sends one copy of the message per recipient. This way it can implement VERP (Variable Envelope Return Path), a nice feature for mail lists.

Setting concurrencyremote to 1 and limiting the connection rate should do the trick.
_________________
Javier Miqueleiz

"Listen to your heart. It knows all things, because it came from the Soul of the World, and it will one day return there."