Render unto sysadmin what is sysadmin's!
Yes, my internal DNS was saying smtp.netjungle.it is 127.0.0.1, and my /etc/hosts was saying it's the public IP.
I kept the Split DNS configuration but it's just for a firewalled installation.
I think it will be ok next time I try to move it.
Many thanks, I owe a pint of beer to you.
