[Sig] Mail Client (sender) that can be driven from the command line -- recommendations?

[Randy Kramer]

I have a TWiki partially installed at home.  (It is not completely or correctly configured yet.)

It can send email notification of changes (and email notice of successful registration) using a Perl program -- the Perl program formats a message and then issues a command to sendmail.

I'd like to find another (Linux) mail client that can be driven from the command line.  Anyone know of any?

I would expect that this ability is not that uncommon -- under Microsoft, Visual Basic programs can call either Outlook or Messenger to send email under program control.

(Sendmail is not configured on this machine, but I can send mail from this machine using any email client configured to use my ISP's smtp account.)

Thanks!
Randy Kramer

PS: For anybody who is really interested:

The mail program is specified in a configuration file like this:

$mailProgram      = "/usr/sbin/sendmail -t -oi -oeq";

The mail program is invoked from a Perl subprogram (method?) like this:

sub sendEmail
{
    # Format: "From: ...\nTo: ...\nSubject: ...\n\nMailBody..."                       
    my( $mailText) = @_;
     if( open( MAIL, "|-" ) || exec "$mailProgram" ) {
        print MAIL $mailText;
        close( MAIL );
        return "OK";
    }
    return "";
}              

In another Perl program, the sendEmail method is invoked like this:

if( ! &wiki::sendEmail( $text ) ) {
        print STDERR "- ERROR: TWiki mailnotify can't send mail\n";
        $debug && print "- End Twiki.$webName\n";
    } else {
        $debug && print "- End Twiki.$webName, mail notification sent\n";
    }                                     

After several commands to format the message, like this:

    $text = &wiki::readTemplate( "mailnotify" );
    $text =~ s/%EMAILFROM%/%WIKIWEBMASTER%/go;
    $text =~ s/%EMAILTO%/$notifylist/go;
    $text =~ s/%EMAILBODY%/$emailbody/go;   
    $text =~ s/%TOPICLIST%/$topiclist/go;
    $text =~ s/%LASTDATE%/&wiki::formatGmTime($prevLastmodify)/geo;
    $text = &wiki::handleCommonTags( $text, $topic );