I'd like to tighten up some of my basic rules. I'm aware that when setting up a rule for http port
80 that you must allow an external range of 1024 - 65535 to 80 but what about some of the other
services? Is DNS 53 to 53, smtp 25 to 25, pop 110 to 110 or do they have external ranges as well? Is
there a master list that outlines all the protocols? 

TCP/UDP  	 *  	 *  	 master  	 53 (DNS)  	 NAT DNS server   	
TCP 			* 	* 	server 	443 (HTTPS) 	NAT ssl server  	
TCP 			* 	* 	master 	25 (SMTP) 	NAT smtp server  	
TCP 			* 	* 	master 	110 (POP3) 	NAT pop3 server