Greyfix is much like postgrey or sqlgrey in that it does the same thing when it sees a mail for the first time. The actions are identical, but greyfix is much lighter than any of those. Yes, you'll see those processes running because greyfix is setup to kill old processes and start new ones. This keeps the processes running and stops any from locking up.
As for the whitelist entries, what I've done with this Snake was setup a global whitelist. If you log in to Baruwa --> List, you can add whitelist/blacklist entries. These entries are queried by postfix using the mysql-global_whitelist.cf file. If an entry is found in the whitelist, it bypasses grey, rbl, spf and mailscanner checks. This was something I thought long and hard about because I wanted to have a common whitelist.
As for running multiple instances, the developer of Baruwa has that on his roadmap. He's going to develop Baruwa so that we can use a common database. Of course this is a way down the line.
Give it a go, test it out. I think hooking Baruwa into the common db will be the trick, but the mysql replication is not hard at all.
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