William wanted to do something similar and also achieved it.
For the spamlist problem I have there are two solutions:
1. Use another IP from Exim4U, which you say that MULTI_IP will solve.
I probably need to upgrade to newer version, because I don't have the option to assign an IP to the domains. Do you know why?
2. Use Exim4U for receiving and temporarily set a smarthost for it, so that when it receives an outgoing mail it then sends it to another smarthost, thus I am hoping that that smarthost will be checked only for spamlists. Can this be easily achieved?
Thank you,
Daniel