There are several Dreamweaver extensions that offer email handling [of a sort] that I know of.
Examples are NeXTensio2 combined with PHAkt2 which rely on using server behaviours [PHP, ASP, ColdFusion etc] while others are basic, pre-built PHP forms. A quick search on the Macromedia Exchange for the word email in the Dreamweaver section will return a few possibilities. Most of them cost though.
To get your FormMail script to work properly at a basic level you need to include these fields in your form:
<form name="form1" method="post" action="/cgi-bin/FormMail.pl">
<input type="hidden" name="subject" value="Title of the email subject" />
<input type="hidden" name="redirect" value="Full URL including http of the 'thank you for contacting us' page" />
<input type="hidden" name="recipient" value="email address of the recipient" />
The first section is obviously the location of the FormMail.pl script on your web server. The second assigns a subject to all emails sent from the form, the thrid redirects people who submit the form to a 'Thank you' page and the fourth should contain the email address of the person to receive the emails.
The FormMail.pl script itself needs minimal adjustments in most cases for basic operation. Make sure the first line in the FormMail script is correct - get this information from your web host:
The next uncommented line is the address of your email program script on the server - again, get this information from your web host, but it is normally:
$mailprog = '/usr/sbin/sendmail -oi -t';
Next you should alter the @referers line as follows:
@referers = ('your site URL without www','your site URL with www','you can use localhost as well if required');
Note that the referers list is in this form (',',') and that missing out the brackets of single quote marks will make it all fall over.
Finally all you need to do is edit the @recipients line as follows:
@recipients = &fill_recipients('your site URL without the www','again you can leave localhost in if required');
Make sure you have both the cgi-bin folder and the FormMail script chmod to 775 or to -rwxr-xr-x if you use WS_FTP Pro and make sure any editing of the FormMail script is done using a simple text editor like Notepad. Word processors mess up FormMail scripts like you wouldn't believe.
I'd suggest that you remove the existing FormMail script and try it again by modifying your original as I've outlined above. Include the form fields and just do the FormMail modifications I've listed, upload, chmod and see what happens.
Most errors with FormMail are either down to incorrect chmod settings or incorrect configuration in the script itself.
Post back with the results.