This is a function of your mail software.  The way to get around it is to use Listserv
continuation format when processing commands that are longer than 80 characters.
 Here is the excerpt from the manual:

//<space><beginning of command><space><comma>
<continuation of command><space><comma>
<continuation of command>....

On 26 Oct 2000, at 12:03, John Castilla wrote:

> I have been trying to figure out why there is a carriage return after
> the 79th character. If I send from a web based email address this does
> not occur. Only when I send it through Listserv does this occur. Do you
> know if there is a setting which I can tweak for line width or am I
> looking in the wrong direction. Below is a sample of what I sent to
> Listserv and received back.