You can delete it through your Account/ My Nook Library on bn.com, can't delete it directly from the device.
I'm using Pulse and it doesn't ask for my email address, nor does it have it. I wonder if you have selected google or facebook or similar news feeds?
Having a similar issue but only when trying to add Facebook feeds to Pulse. Otherwise, the app works fine. Hopefully that will get fixed.
I installed Pulse and it immediately went into an email set up page EXACTLY like the preinstalled email app that came with my NookColor. I've tried uninstalling it and reinstalling it twice. I give up.
Open the Email app on your Nook Color and then follow these steps.
1. Launch the NOOK Email app.
2. Tap on the Account button. (2nd button at the top)
3. Tap "Accounts", and then choose (check) the email address that you
want to remove or log off.
4. Tap the "Trash" icon at the upper-right hand corner to remove