Completely baffling LuaSocket SMTP problem

[mchalkley@...]

Hello,

I'm just getting started with Lua and I'm trying to use luasocket (Lua
5.1.5, LuaSocket 2.0.2, Windows 7) to send an SMTP message.  I keep getting the
following error in my program, even though I can remove the code
and put it in a standalone script and it works fine.

The code is copied directly from the luasocket reference page, fwiw.

lua: C:\Lua\bin\..\lib\lua\socket\tp.lua:51: attempt to call field 'type' (a string value)
stack traceback:
        [C]: in function 'send'
        sysagent.lua:233: in function 'SendSMTPMsg'
        sysagent.lua:23: in function 'LogIt'
        sysagent.lua:479: in main chunk
        [C]: ?

I've tried everything I can think of, even down to replacing all the
variables with hard-coded strings.

Any ideas on how I can narrow down what this error means?

Thanks,

Mark