Should you accidentally delete the default account, you can recreate it using the x-add-default command:

popstore> x-add-default

You can then set settings for the default account using the modify command:

popstore> modify default -quota=1000 -overdraft=15

6.17 Recreating the User Database

popstore> x-build-user-db

This utility will create a new user database and populate it with entries found by scanning the profile directory tree.