I can't find where the ubuntu (and debian) exim override my smtp_banner setting.
It doesn't seem to matter what I set it to, most of the time when I telnet to the server on port 25, I just see:
220 ********************************************************************
I only seem to be able to see the banner if I connect from localhost or to port 587.
I haven't managed to find anything in the documentation, or in the apt source exim4 files, or via websearch that explains why this is happening and how to make the banner always visible.