I need to check if an e-mail exists in the system so that, if it does, we can send a password reminder.
If it doesn't, I need to display an error message.
Effectively we'd need to set up a simple search form here, to query the database. If TotalRows are 0 then it's safe to assume that the e-mail address doesn't exist and we can display an error message accordingly etc.
I think I was just stuck in using, completely, the WA Server Validation behaviour for this and then a double negative happened and my brain popped.