So now you have a Pocket PC and you can access your internal network via a VPN (Virtual Private Network) or RAS (Remote Access Server). If you can't, check out my last article, "Changing Network Systems," Pocket PC magazine, Sept. 2002, p. 61. This time let's focus on e-mail systems and the ways in which the Pocket PC can integrate with them. Users of Internet e-mail may find parts of this article helpful in addressing specific configurations that are not standard.

E-MAIL PROTOCOLS

Let's start with a basic overview of the Inbox functionality of the Pocket PC 2002. The Pocket PC 2002 supports the following e-mail protocols--POP3 (Post Office Protocol 3), SMTP (Simple Mail Transfer Protocol), and IMAP4 (Internet Messaging Access Protocol 4). Users should note that there is no MAPI client (native Microsoft Exchange Client) available--I'll cover how to work around that later. To the POP3 and IMAP4 functionality, the Pocket PC 2002 adds the ability to send e-mail with Secure Password Authentication (SPA). If you need SPA support and don't have a Pocket PC 2002, check out nPOP (www.nakka.com) for an SPA-compliant e-mail client. There is support for LDAP (Lightweight Directory Access Protocol) if you have it available in your environment. Of course, you can use ActiveSync to sync your e-mail as well. Also, Microsoft offers Outlook Web Access (OWA), but it is not compatible with the Pocket PC. However, Microsoft offers an ASP Web client that is compatible with the Handheld PC and Pocket PC for free (www.microsoft.com/mobile/handheldpc/dowloads/mailclient/mailclient.asp). Note that the Inbox application does not support SSL (Secure Sockets Layer) encryption of all data sent and received. The Pocket PC 2002 added support for some HTML e-mail. However, in some cases the HTML is not parsed.

So in order to get e-mail directly into your Pocket PC, your company will need to support POP3 or IMAP4. IMAP4 is the preferred solution for accessing e-mail because all your e-mail is stored on the server in folders. With IMAP4 you can access past e-mail if it is still available on the server. Further, IMAP4 is more efficient since you get a list of e-mails to look at and then you select which e-mail you want to read and it is downloaded for you to view. In comparison, POP3 only offers the ability to retrieve new e-mail received. All old e-mail is stored on your PC or Pocket PC, and it is deleted from the server unless you select the option to leave it on the server. Also, all POP3 e-mail is downloaded at once, so you have to wait until it's done. In both cases, deleting e-mail on your Pocket PC will delete e-mail on your server, so be careful! Before implementing e-mail on your Pocket PC, I would suggest installing update EUU1 from your hardware manufacturer as well, since it resolves many connectivity issues.

SECURING THE E-MAIL SERVER

Here are some options that you as network administrator can use to better secure the e-mail server. I'm sure you are concerned about opening up your e-mail server to people who could send spam. First, I suggest that you implement SPA to prevent unauthorized users from sending e-mail through your server. Second, I would recommend limiting e-mail to e-mail addresses from your domain only. This prevent end users from spoofing the reply address to another domain. Lastly, if your server does not support SPA, consider limiting the IP addresses by which users can access the e-mail server, thus reducing the possibility of a third party using your server. The IP addresses should be the internal IP addresses of your network only. If you are using NAT and RAS or a VPN, only individuals with RAS or VPN accounts can access these IP addresses.