It's a carrier thing.
Some carriers, for whatever reason, have quietly done away with their BIS page. Use the Setup application they said. Well and good, but there were issues with some devices that wouldn't let a user add/remove/edit any accounts that were tied to the device. So, go use the BIS carrier page. Yeah, uhmmmm doesn't exist for some carriers. Others have moved to a web-based BIS portal linked with the actual corporate carrier site
Normally (well, since June anyways), if you wanted to associate an e-mail account to a BlackBerry device (BIS account actually) you would follow the directions in KB02189. If that didn't do it, you would move on to KB10453 (Unable to integrate an e-mail account with BIS account) which covers almost everything except OWA. If you scroll down to Cause 1, under resolutions, you'll see a link to an Email Account Validation Tool, or eavt.
If you were to visit www.blackberry.com/eavt
from any browser, you would see that you can test each account you have associated with your BIS account. but you can do this from a PC, whereas with the /integrate method, you can't. I don't know about anyone else, but I had 10 accounts tied to my BIS, and I am not checking them individually! If someone is having an issue with one account, I will more often than not, send them to the eavt, but if a user is having an issue with all mail, then integrate from the device browser is usually my answer. If that fails it's either a messaging server issue or a carrier issue, user error or RIM's network down.
What does it do? Exactly what it says, it will register you on the BB Network and then try to reintegrate all e-mail accounts associated with your active BIS account (regardless of device) That is what integration means. Registering the HRT [Host Routing Table] (Go to Options, Advanced Options, Host Routine Table. Hit Menu and select Register Now) IS registering you on the BlackBerry Wireless Network. Resending your service books (Setup>Mail Account>Login with password>BB Menu button>Service Books>Resend Service Books) will allow you to receive the provisioning and services that your carrier has included.
Why use it? A couple of reasons. As I mentioned above, it clears out a lot of troubleshooting in one fell swoop. A few steps are bypassed that may seem pretty easy to you and I, but some just want a streamlined way to do it.
Must be done from your device browser.
[What it does]
Registers the device on the network (HRT)
Tries to resend all associated service books to your device
Tries to reintegrate all e-mail accounts associated with your BIS account.
[What's the worst that could happen]
You may be asked to enter your credentials (User Name and Password) for one, or all of your associated e-mail accounts. These reasons could include credential errors (mistyped passwords), incorrect messaging server information. Before doing this, have all your information close at hand, in case you have to add an account that was deleted for whatever reason.
Can be done from any browser
[What it does]
Used to validate the integration of an e-mail account
[What is the worst that could happen]
Not a thing.