I'm having a problem where visitors are receiving two emails when they register for an new account. One email has a welcome message that I have set, and one is empty. I want to disable the sending of the second, empty email. I need help in tracing which plugin or mechanism sends out the empty email in order to disable it.
Background: When people register for an account, their account is not immediately activated. An admin needs to validate accounts by hand first. I'm using Gravity Forms with User Registration add-on for this.
I'm using SB Welcome Email as a plugin to set a custom welcome message to people who have registered for an account. However as mentioned above, there are now two emails being sent to the user. One by SB Welcome Email (good) and one empty (bad). Any suggestions on how I can trace which plugin is sending the second one, and / or any help on disabling the empty email?
Also helpful: which hook or action is called when a new user signs up for the site?