I apologize if the wording of this topic sounds weird, but it's the best way I can describe it.
So, my setup is as follows. Internet connection goes into server machine running Slackware (eth0), and gets an IP via dhcp. I'm running Shorewall on the Slack machine, and eth1 goes out to a router, which supplies the internet for the rest of my lan. This all works fine. My domain is pointing to the IP that the slack machine gets, and I'm running Bind9 on it, so it acts as its own DNS server. This is also working fine. I'm also running Apache2 on the server, and again, this is working.
However, on my desktop machine, running Ubuntu Breezy, I can't access my domain. Like, if I open a web browser and try to go to www.mydomain.com, it times out trying to get there. But, if I just put in the IP address, it pops right up. Also, the domain is fully accessable from outside my LAN. Email is another problem. Sendmail and popa3d are running on the server as well, and I can recieve email fine, but it's having problems sending it. It usually takes 2 or 3 tries of hitting Send/Recieve (Evolution and Thunderbird) for the mail to actually get out. The maillog on the server machine has started spitting out "lost input channel from XXXX.domain.com [192.168.1.101] to MTA after mail". From searching google, I think that message has something to do with spam blocking? I don't understand why this has all started happening, as it was working fine before now, and I haven't changed anything.
This is all very frustrating, because I can ssh and ftp to the server from my desktop. Everything seems to be fine unless it involves the domain name.
Hopefully I've described this problem well enough that someone can help me troubleshoot it.
Thanks in advance for any ideas/suggestions.

Mike

I'll deal with the website viewing;

When your browser sends the request for the url, the nearest domain name register will translate this into your ip number. Since the request is coming from the same ip number it gets confused and refuses the connection. You can use local network loop back or configure your browser to use a public proxy server or you can use another method of connection to the net to do this.
Cannot help with your email problem but I run postfix on my server and relay the mail through my normal isp mail server.