Many thanks! That should get me going.
The interfaces are apparently numbered ("smtpd1", "smtpd2") in main.cf
in the order they appeared in master.cf while the "smtpd" remains the
default (unless disabled). If I disable the default in master.cf, does
the first interface-specific smtpd become "smtpd" without a suffix or
does it remain enumerated since it's not generic? I'll find that out
in a few moments, but I'm guessing it remains enumerated because
otherwise smtpd_* params in main.cf would not refer to a specific
interface as would be intended, and there would not be a way to define
global smtpd_* parameters.
