uhh... I think he's asking how to sync 5 different email accounts that are in Outlook via ActiveSync. As far as I'm aware there's no way to do this using the native Email/ActiveSync (right out of the box) because by default it only syncs the Inbox of your default Outlook profile and any SUB folders that you specify.
That said, you can easily add POP3 accounts to your device Outlook by simply adding other accounts. The down side is that they WON'T sync back to your desktop computer.
OK, now on to what MIGHT be good news: there are 3rd-party apps out there that may do what you want.
1.
Pocket Lookout by Vonken Software allows you to sync ANY folder that is in your Outlook hierachy. The downside appears to be that you have to use their GUI on your PocketPC (which makes since).
2.
IntelliSync looks like what you want, but I'm honestly not sure.
3. I personally use
FlexMail 2006 by WebIS. This allows me to check whatever email I want while I'm mobile but still allows me the safety of archiving email on my desktop. The downside is that I have to deal with some email twice (because I leave email I've checked while mobile on the server until I download it to my desktop).
There are probably others out there (go to handango.com and search for synchronization).
I guess the first thing you have to figure out is if you really want to sync, or are you just looking to get a hold of your email? If it's the latter, then go with a solution like #3.