If the problem occurs for incoming connections, and you
are using some sort of port fowarding via your NAT-address
to get the actual TCP/IP connection to your mail server, maybe
your NAT router setup is randomly dropping (incoming) connections.
Some low quality hardware does this for incoming connections (I still
own
such a device myself).
That should create a temporary problem during the data
part, but there should probably be messages in your
logs about lost connections then.
Or maybe your exim is configured to do certain things
in the data acl and those somehow fail?
On Mon, 2007-06-25 at 18:11 +0100, John Clement wrote:
> Thanks for the reply, this is all relating to incoming mail for our
> domain. I agree the MX config is more than a little unusual. The 1st
> and last entries are are a dummy entry, from what I understand this is
> to reduce the amount of spam we receive (the way the guy that set it up
> this way explained it to me is spammers usually hit the first mail
> server, find its down and give up), moving onto the real servers one is
> the actual server (that we've got the problem with - mx3) and the other
> two are servers that just forward to mx3.
>
> Any more thoughts?
>
> thanks - jc