On Tue, 2012-09-04 at 00:53 -0400, Phil Pennock wrote: > On 2012-09-02 at 10:40 +0100, Ron White wrote: > > Can anyone on the list tell me if it's possible to performance tune Exim > > to a point where it could complete with this and possible strategies? > > You don't mention the number of machines used. > > It would require C language level changes to Exim, or some complex > configuration, to change from the current spool model to something which > manages destination queues and shuffles mail between them. > > I could do it as a configuration-only thing, and with documentation it > would be maintainable, but I'd use it as an opportunity to study what > was needed and find ways to move it into the core to be more easily > configured as a stock option and reduce the technical debt of the > configuration maintenance. > > Exim's not geared, as is, for large backlogs. With enough grunt, you > can overcome that, but it won't be as capable as a major email-pushing > engine. > > Note that Exim's bias is towards stability; the > one-process-per-connection model (both inbound and outbound) means that > one weird remote site can't screw up other deliveries. If you have an > MTA which never does TLS, doesn't worry about inbound connections except > enough to handle callout verifications, and where the volumes are enough > that a few connections dying at once is statistical noise, you can swing > the bias to optimise for outbound throughput instead. > > I think it's PowerMTA that I looked at back in January or so, and if > I'm remembering the right product, it's got support for web-bugs and > other tricks to try to get status feedback from HTML-enabled > mail-clients, to try to gather deliverability statistics, and it's all > tied into some nice dashboards. If a marketing department is looking at > this, you've got a bunch of work to do to compete. The MTA I looked at > was quite nice, at a technical level; it took to heart the C10k lessons > and, from the paper blurb, gave my cynical side pause enough to be > willing to take a serious look. That doesn't mean I ever want a job > _running_ a closed source MTA. *shudder* Being a postmaster has enough > problems already, without having a product you can't investigate and fix > yourself, when you're talking to so many different products at remote > sites. MTAs are one product that _seriously_ benefit from having the > source. But that's my bias. And hey, I ended up becoming an MTA > maintainer as a result. > > Most open source folks don't send high volumes of identical mails, so > there hasn't been the push to develop an open competitor, so the > closed-source side has more options here. > > -Phil > Thanks Phil,
I agree that Exim is not specifically designed to do the same job as something like PowerMTA - and I'm very happy with my Exim(s) doing what they do. Curiosity and general discussion with a large newsletter mailer brought the question up for me, and I just thought I would ask it on a trusted list. It seems by doing this I've caused some kind of offence to some - which totally perplexes me! I don't think there is a huge OS need for an MTA that can maximize delivery. Qmail appears to be configurable to offer similar performance to PowerMTA, but it's not something I have a need to do. I just find the subject interesting. Thanks again for the great response. It's really appreciated. -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
