Check out this link.. FAQ: What Are The Methods of Receiving Email On BlackBerry?
It has the following info ... originally posted by our Super Moderator - Mark Rejhon You will also find lots of information on this in the forum if you do a search.
What Are The Methods of Receiving Email On BlackBerry?
I noticed on several forums that this is a commonly asked question. So I am posting. There are several ways to get emails into a BlackBerry. BlacKBerry does not use a conventional email client, using a push technology. However, you can integrate nearly any email account including POP and IMAP and Exchange and even add support for Hotmail/GMail/etc email accounts.
BIS / BWC email address. (See Glossary) This is the free push email address included with all BlackBerry plans. Most common method for consumers/prosumers. Send the email to the free
email address. This is true push email, as email will show up instantly on the BlackBerry (in just 5 seconds in many cases) the moment someone sends it from a desktop computer. No need to check email, it shows up immediately on your BlackBerry screen, SMS-style or pager-style! To access to your @blackberry.net email account, See BWC/BIS Login Instructions.
Tip For Advanced Users: When adding new POP/IMAP accounts to your BWC/BIS account, try entering dummy information for username/password. This will get you straight to the Advanced Server Page, which allows more configuration such as for Secure Password Authentication, etc.
POP and IMAP email. This is available with all BWC accounts above. The BWC webmail site has a configuration that allows you to enter POP hostnames, usernames and passwords for a certain number of POP accounts. Your BWC will automatically check email every 15 minutes and forward a copy of messages to your BlackBerry. This is not true push email; you must send email directly to the @blackberry.net address (or use BES). Information from BlackBerry website
Email forwarding. Configure your existing email addresses to automatically forward a copy to your BWC email address (the one ending in blackberry.net). This will allow you to have a different email address while retaining push email capability, for those cases you do not need a BES.
Third party email software such as Reqwireless EmailViewer or HotViewer or midlet-based email client. These software are not as good as the built-in BlackBerry push email but you can get third party email software and install them on the BlackBerry for those special exceptions that you don't want to integrate directly into the BlackBerry. Note: In order to be able to run third party email clients on the BlackBerry, you need either (a) BlackBerryOS 4.0 or later, or Nextel/Telus BlackBerryOS 3.7 or later ..... or (b) use a Blackberry Exchange Server, or a BES/MDS hosting service.
BlackBerry Redirector. This is a special software program included on a CD included with BlackBerries, that you can install on your computer. You can run it on a home computer or office computer -- just leave the computer on 24 hours a day. The software will watch for new emails arriving in Microsoft Outlook and then automatically forward a copy of these emails to your BlackBerry. (No BES needed). But you must keep your computer running 24 hours a day to get copies of your email.
Blackberry Enterprise Server (BES). This can be purchased as a server for full internal integration with corporate email, (expensive) or as a BES (MDS) Hosting service for more individual integration (cheaper). Mainly used by corporations, although some prosumers have purchased BES/MDS Hosting services. This is the preferred corporate method of push email, fastest and most secure, and allows you to have your own custom domain names. It interfaces with Exchange Server (or Lotus Domino, or soon Groupwise) and allows your BlackBerry to automatically mirror your Exchange Inbox. Wireless email sync capabilities means that if you delete email on your BlackBerry, it also gets deleted from the desktop. There are other benefits to BES. For example, Version 4.0 of BES also adds wireless over-the--air Addressbook/Calendar/Notes/Tasks synchronization. More information for the full corporate version is found here. Alternatively, you can get BES Hosting Service if you don't want to purchase the full server. The full server itself can cost over a thousand dollars, while getting hosting service for one BlackBerry typically costs less than $25 per month.
All five of the above can be used simultaneously on different email addresses, into the same BlackBerry "Inbox" (Messages screen).