
<li> <tt>server</tt>: Server to connect to. Defaults to "localhost";
<li> <tt>port</tt>: Port to connect to. Defaults to 25;
<li> <tt>domain</tt>: Domain name used to greet the server; Defaults to the
local machine host name; 
<li> <tt>step</tt>: 
<a href="http://lua-users.org/wiki/FiltersSourcesAndSinks">LTN12</a> 
pump step function used to pass data from the
source to the server. Defaults to the LTN12 <tt>pump.step</tt> function;
<li><tt>create</tt>: An optional function to be used instead of
<a href=tc