<< I think this may be the most appropriate.
You mentioned that the site is stored in public_html/mcsjlc/wedding - so I'm guessing now that it's an addon domain (you have more than one domain on your account perhaps). At this stage, I'm just going to have to tell you what I'd be doing in this situation to troubleshoot the issue. (It was so much easier when I was in tech support - you have access to the things causing the problems
Anyhow, the next thing I would try is probably to create a copy of the .htaccess in public_html/mcsjlc
In the event of having an addon domain, the folder you put it into becomes the public_html folder for that domain. So if your main domain was "mydomain.com" and your addon domain is "mcsjlc.com" then:
public_html = the public_html folder for "mydomain.com"
public_html/mcsjlc = the public_html folder for "mcsjlc.com"
I may be barking up the wrong tree here, but given that the form mail script has pretty good error handling in it, the fact that you are not receiving an error message from the script makes me think that the server isn't actually hitting the script.
The other thing that comes to mind (and this depends on how LunarPages servers are set up these days - I'm a few years out of touch now), is where the cgi-bin is located. Obviously the instructions say to put the script into public_html/cgi-bin - part of me would try duplicating it in public_html/mcsjlc/cgi-bin. However, that is only because I don't know these days whether addon domains refer to the root public_html folder for the cgi-bin folder.
One way or another we'll get to the bottom of this... May need a lot of coffee though