I can see you’ve posted your Caddy version and Caddyfile (thanks!), but there’s a lot more information missing. At a very quick glance, I can’t see anything glaringly wrong with your Caddyfile, so your problem is likely a bit more complex.
(I’d be remiss not to mention, too, that Caddy has had an entirely new version released since v1, rewritten from the ground up and much improved! You might consider upgrading to the new Caddy v2.)
There is a Help topic post template that outlines some of the information needed to point you in the right direction. If you can fill it out, you’re much more likely to get better help.