Re: [exim] Greylisting - using Exim new features - ratelimit…

Ian Eiloart wrote:
>
>
> --On 11 July 2007 06:57:20 -0700 Marc Perkel <marc@???> wrote:
>
>>
>> I'm using a different failover system. I have a main server on the low
>> mx and several backup servers on the next highest mx.
>>
>> dummy0.junkemailfilter.com - 10 - semi-dead IP
>> mx.junkemailfilter.com - 20 - main server
>> mx.junkemailfilter.net - 30 - multiple backup servers
>> mx.junkemailfilter.org - 40 - several IP where I log connect attempts
>> dummy1.junkemailfilter.com - 50 - several IP where I log connect
>> attempts
>>
>
> Hmm, that's just a case of having backup servers. Works fine for
> ordinary SMTP, but isn't good enough for MUAs. When we set up our
> cluster, we set up the 4 machines on a round-robin DNS, so
> smtp.sussex.ac.uk points to four IP addresses. That seems to work well
> with MTAs, but doesn't work at all with MUAs.
>
> In order to provide high availability message submission, all four IP
> addresses have to be available at the same time. That's why we
> introduced IP failover. In theory, any one of the four machines could
> support all four SMTP IP addresses at the same time.
>
> We use spread/wackamole for failover, and it works really quite
> nicely, though not perfectly. I'd estimate that downtime is reduced by
> an order of magnitude.
>

In my case I have a separate server for people to get their mail from.
Incoming email goes to the front end spam filters, the spam is removed,
and the good email is forwarded to other email servers where the users
get their email.

BTW, Ian, What do you use for a pop/imap server that runs across several
computers?