Re: [exim] MDaemon and dynamic screening

Exim is not at fault at all. This is all due to the famous buggy server
Mdaemon. The antispam configuration on Mdaemon is quite a bit weird if
you expect real mails to be delivered.
If a 5xx error (permanent) is delivered, your exim will of course create
a bounce message signalling to the sender that the message could not be
delivered. In no way you can test the existing users on your client's
server (recipient callouts will also be refused anyway), except if they
give you a list of existing users that you can integrate into your exim
config, but that much of a hassle to configure. Now if Mdaemon decides
to block everything from your IP just based on the fact that people sent
some mails to wrong addresses, you cannot do anything about that on exim.
If you had configured recipients callouts, you wouldn't have sent any
bounce, but further messages would have been refused anyway.

John Oxley wrote:
> I have a client that I am relaying mail for. They are running an MDaemon
> 9.05 server with dynamic screening turned on. What this does is after 3
> unknown recipients it sends a 550 error to the sending host which is my
> exim box. Then for the next 10 minutes, whenever my exim box connects to
> the MDaemon server it gets sent a 550 error before the SMTP banner comes
> up.
>
> My exim box then bounces that email because it has been given a 5xx error
> message. What I want to know is if my exim box is behaving correctly. I
> assume that it is because 5xx messages are permanent and 4xx are
> temporary. I have turned off dynamic screening and this problem is not
> occurring anymore, but I now have to explain to management types why the
> problem happened in the first place and I want to cover my back that exim
> is not at fault.
>