Re: [exim] increase in smtp concurrency

John Horne wrote:
> On Tue, 2007-09-11 at 17:01 -0700, Marc Perkel wrote:
>
>> John Horne wrote:
>>
>>> On Fri, 2007-09-07 at 14:56 +0100, Chris Edwards wrote:
>>>
>>>
>>>> Anyone else noticing more concurrent incoming SMTP connections in last
>>>> couple of weeks ?
>>>>
>>>>
>>>>
>>> May I ask do you mean concurrent as in from the same sending host, or
>>> simply that you are receiving more connections generally than usual?
>>>
>>>
>>>
>>>> Perhaps it's time to switch our DNSBL etc tests from "deny" to "drop" mode.
>>>> Is there any obvious downside to this ? Do most folk use drop already ?
>>>>
>>>>
>>>>
>>> I've been running one of our mailhubs with a 'drop' instead of 'deny'
>>> for the past few days. No problems reported.
>>>
>>>
>>> John.
>>>
>>>
>>>
>> Just a thought. Maybe you could do a rate limit in the NOTQUIT acl to
>> slow down IP addresses that don't send a quit?
>>
>>
> Surely imposing any sort of delay will cause more connections to be used
> up though? Or rather it will delay connections to become free, and thus
> make the problem worse.
>
>
> John.
>
>

The NOTQUIT is mostly all spam and spam doesn't retry.