<div>
or... if its behind your firewall and NAT'd on an invalid address, why not simply do port forwarding on your router for POP3 to your mail server's IP address then you can just check mail from the public address.. <br />
<br />
so.. on router something like :<br />
<br />
ip nat inside source static tcp &lt;IP Address of mail server&gt; interface &lt;public interface (ethernet0) 25<br />
<br />
<br />

</div>


or... if its behind your firewall and NAT'd on an invalid address, why not simply do port forwarding on your router for POP3 to your mail server's IP address then you can just check mail from the public address..

so.. on router something like :

ip nat inside source static tcp <IP Address of mail server> interface <public interface (ethernet0) 25




<div>
sorry i misread your post.. you CAN do it externally.. not internally.. Dimarc67's answer will work, or you could just set your POP3 to the internal IP address of the mail server.. 
</div>


sorry i misread your post.. you CAN do it externally.. not internally.. Dimarc67's answer will work, or you could just set your POP3 to the internal IP address of the mail server..

<div>
<div class="content wysiwyg-content">
I setup POP3 on my exchange server and I can access it when I am outside the building. But once I am inside the building, it can not connect to my pop3 account. I'm guessing this is a local dns setting but not sure where or how to add it. &nbsp;I use a laptop and take it home with me each day.
</div>
</div>


I setup POP3 on my exchange server and I can access it when I am outside the building. But once I am inside the building, it can not connect to my pop3 account. I'm guessing this is a local dns setting but not sure where or how to add it.  I use a laptop and take it home with me each day.

Can't access POP3 when in local area network

The Windows operating systems have distinct methodologies for designing and implementing networks, and have specific systems to accomplish various networking processes, such as Exchange for email, Sharepoint for shared files and programs, and IIS for delivery of web pages. Microsoft also produces server technologies for networked database use, security and virtualization.

Windows Networking

The Domain Name System (DNS) is a hierarchical, globally distributed system responsible for associating the name of a computer, service or other resource into an IP address for connecting to the Internet or a private network. Most prominently, it translates domain names to the numerical IP addresses needed for the purpose of computer services and devices worldwide.

Interactions between email servers and clients are governed by email protocols. The three most common email protocols are POP, IMAP and MAPI. Most email software operates under one of these (and many products support more than one).  The correct protocol must be selected, and correctly configured, if you want your email account to work.