Accessing Corporate E-Mail
By Chris De Herrera, Copyright 2002, 2003
 Version 1.03  Revised 1/9/2003

So now you have a Pocket PC and you can access your internal network via a VPN or RAS (if you can't check out my last article!), let's focus on accessing e-mail. My discussion about e-mail will focus on a variety of 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 to address specific configurations that are not standard.

Overview of Inbox

Let's first 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. In the POP3 and IMAP4 functionality, the Pocket PC 2002 adds the ability to authenticate to send e-mail using Secure Password Authentication (SPA). If you need SPA support and don't have a Pocket PC 2002, check out NPop ( http://www.nakka.com ) for a SPA compliant e-mail client. Also, there is support for LDAP (lightweight directory access protocol) if you have it available in your environment as well. Of course you can use ActiveSync to sync your e-mail as well. Also, Microsoft offers Outlook Web Access (OWA), however the version that ships with Exchange 5.5 it is not compatible with the Pocket PC. With Exchange 2000, Outlook Web Access is compatible with the Pocket PC. However, Microsoft offers an ASP web client for Exchange 5.5 that is compatible with the Handheld PC and Pocket PC for free ( http://www.microsoft.com/mobile/handheldpc/downloads/mailclient/mailclient.asp ).  There is a 3rd party ASP solution as well that allows access to your e-mail using OWA and it is formatted for the Pocket PC called OWA for PDA. Also, note that the Inbox application does not support SSL encryption of all data sent and received. You may be able to use STunnel to provide an SSL connection.  See Michael Wm. Gilbert's article on SSL - IMAP to Pocket PC.  One last thought on e-mail, the Pocket PC 2002 added support for some HTML e-mail. However in some cases, the HTML is not parsed.

Protocols

So in order to get e-mail directly into your Pocket PC, your company will need 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 also suggest installing EUU1 from your hardware manufacturer as well since it resolves multiple connectivity issues.

Security

Here are some options that network administrators can use to better secure the e-mail server. I'm sure they are concerned about opening up their e-mail server to people that could send spam. First, I suggest that you implement SPA to remove the ability of unauthorized users to send e-mail through your server. Second, I would recommend limiting e-mail to only e-mail addresses from your domain. This removes the ability for end users to spoof the reply address to another domain. Last if your server does not support SPA, consider limiting the IP addresses that the users can access the e-mail server with so you reduce the possibility of a 3rd party to use 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.  Another option for administrators is to enable POP before SMTP Relaying.  This means that a user must receive e-mail from an IP address before being allowed to send e-mail using that IP address. This is a good way to control the SMTP port usage without restricting users ability to use any TCP/IP connection available, however it does leave the SMTP port open for a short period of time (usually 5 to 15 minutes).

Changing Ports

Also, in some environments, the network administrator has setup the mail server to use different TCP/IP ports for POP3 and IMAP4. By default the Pocket PC does not allow the user to change these ports. However, in the Pocket PC 2002 you can change the ports with a registry editor ( http://www.phm.lu/Products/PocketPC/regedit.asp ). Note: Performing changes to the registry is not supported by Microsoft or your hardware manufacturer. The ports can be changed in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Inbox\Svc\IMAP4 and HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Inbox\Svc\POP3 respectively. The key name is Port and the value is the port to use in either hex or decimal. I do not know of a way to change the SMTP port based on my review of the registry.

Configuring Exchange

So let's get started covering where to get the information to configure your e-mail server. If you are using Exchange, I suggest checking out the white papers that Microsoft has. For Exchange 2000, start with Configuring Microsoft Exchange 2000 Server for the Internet ( http://www.microsoft.com/exchange/techinfo/deployment/2000/E2KInternetConfig.asp ). In addition they also have step by step instructions to configure Exchange 5.5 for IMAP4 and POP3 ( http://www.microsoft.com/Exchange/en/55/help/default.asp?url=/Exchange/en/55/help/documents/server/XOG15010.HTM . Microsoft also has configuration information for LDAP ( http://www.microsoft.com/Exchange/en/55/help/default.asp?url=/Exchange/en/55/help/documents/server/XOG16002.HTM ) If you are using Exchange, you may have to use a different format to login to Exchange from your Handheld or Pocket PC. The format for IMAP4 is <Windows_NT_Domain>/<Windows_NT_account>/<Exchange_mailbox_alias> with Exchange 5.5. See Microsoft KB article Q220905 ( http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q220905&id=KB;EN-US;Q220905 ) for details. If all you want is to sync your personal and public folders for Exchange, check out Pocket Lookout ( http://lookout.vonken.com/ ) which offers folder synchronization.

Other Servers

Of course, other servers also support POP3, SMTP and IMAP4. Lotus Notes, IBM AS/400 (See IBM Redbook - AS/400 Electronic Mail Capabilities, http://publib-b.boulder.ibm.com/Redbooks.nsf/RedbookAbstracts/sg244703.html?Open ) as well as Linux offer e-mail access that is compatible with the Pocket PC.

Server Sync

There are options that allow users to sync e-mail using the server alone. Microsoft now offers Mobile Information Server ( http://www.microsoft.com/miserver/ ), which works with Exchange. It offers the ability access your e-mail from your server as well as your calendar, contacts and tasks. Microsoft has an article titled How to Install Mobile Information Server 2002 ActiveSync which I recommend you review as well. I also covered other server-based solutions in my prior article titled Synchronizing the Enterprise ( http://www.pocketpcmag.com/Mar02/sync_enterprise.asp ).

SMS - Another Option

I would like to leave you with one last thought. I have been using the Pocket PC 2002, Phone Edition and it integrates SMS into Inbox! So now you can use e-mail on your PC to send an SMS message and a user with the Phone Edition will be able to read it in Inbox! I know it's not the same as e-mail but the user is notified when it is received even if the phone is off. So now SMS is another tool to communicate with users that expands the usefulness of Inbox and the Pocket PC 2002 Phone Edition.