We have an outside spam filtering service for our emails. Our MX records point to the spam filter and then the spam filter points to our mail server.
The outside spam filter wasn't doing a good enough job keeping the spam away. So, I set up the IMF filter on our exchange 2003 server.
The problem is that now we get have one or two email addresses that get blocked by our IMF that shouldn't. Of course, there is no whitelist built in to IMF so to pass false-positives through the IMF I either need a 3rd party tool or I need to use connection filtering.
I've used a few applications for whitelisting like IMFcompanion. It seems like none of them run as a service so as soon as I log out of the server the application closes and the whitelisting functionality stops.
Because of this I decided to try using connection filtering. But the emails are still getting blocked. I'll post the steps that I've taken to configure the connection filtering with hopes that maybe you will catch something that I'm missing.
1) open ESM and go to message delivery > Properties > Connection Filtering > Accept
2) type in the sending server's ip for the blocked emails, 188.8.131.52
3) go to SMTP virtual server > Properties > General > Advanced > Edit
4) I have checked:
Apply Recipient Filter
Apply Sender ID Filter
Apply Intelligent Message Filter
Apply Connection Filter
5) click Ok a few times to finish
6) restart SMTP service.
I've attached an email header from one of the blocked emails that shows the IP address of the blocked email server.