[Zope] mailhosts and mail server speed

[Matt Hoskins]

> Note that if you set up sendmail on a local box, make sure it either
> handballs stuff off to a smarthost straight away, or you have stuff
> set up to check for sendmail getting upset and just queuing messages
> for ever. Normally you'd notice breakages on your mail server - but
> your web server might be a different matter entirely.

I've already dropped chris a mail about the issue. We run exim on our
main mailservers with the configuration such that it verifies envelope
addresses as much as it can (checks the domain exists for remote
addresses). This is likely to cause speed issues, and for mass mailing
or quick mailing from internal hosts it's better to have a different
copy set up to handle the mail (it can even be on the same server, just
on a different port with a different config, assuming the mail send
class being used allows you to specify an alternate port). There are
other config parameters to tweak if large amounts of mail are going to
churn through it to optimise for speed and parallel delivery (if you
queue mail and then send every 15 minutes, you can take advantage of the
fact exim will batch mails if it detects they can go down the same SMTP
connection). Where it's a forking mail server, if you are going to hit
it lots, there's options to configure the limit on accepted
connections/forked copies to stop the mail server grinding to a halt.

Matt