Re: [exim] smtp_accept_max

On Tue, 7 Dec 2004, Tony Finch wrote:

| Our settings are currently:
|
| smtp_accept_max_per_host = 10

Interesting. Glad to hear others are doing this.

The only problem we've had reported with this sort of limit is some
subscribed-for bulk mails from a company called Research Fortnight.
Every day they send "research alert" mails to a couple of thousand staff
here. Whatever software they use has the following two properties:

- It opens ridiculous numbers of parallel connections. We have observed
over 170 connects in a *single second*.

- It doesn't bother retrying in response to 4xx-on-connect. So most of
the mails go down the plughole.

The simultaneous connects is seriously abusive IMO and the lack of retries
is in clear violation of 2821. But the company can't be bothered to
change anything and say they have "no problems with other HEIs".

I'd be interested if any site gets (and more interestingly, defers) mail
from 217.169.39.236.

--
Chris Edwards, Glasgow University Computing Service