Topic: How to make outgoing mail prefer IPv6 connections?
I'm running a simple IRedMailEasy installation in LiNode. They've assigned me an IPv4 address that's in a /24 block that once upon a time had an active spammer. So about half the time, my IP is in a group that's blocked by UCEPROTECTL3. Like anything @live.com, @outlook.com etc.
If I could still have outgoing mail enabled on IPv4 but to prefer sending on IPv6, that would obviate the issue as that v6 block isn't tainted.