Your directory visitors interested in submission to your directory can create an account in order to modify the staff they are going to submit. They have an account area where they can change their personal information like email, name and, of course, listing information.
There can be as many editors as you wish. You can configure your directory to accept listings from registered visitors only. So what this means? Webmasters should create an account and then they can submit a link from an account.
This could be claimed as a very convenient way to gather email addresses.