s2Member allows you to customize some of the emails that WordPress normally sends out, specifically the New User email that the user receives when their account gets created, and the Administrative New User notification email (the email the administrator receives when a new account is created); both of these can be customized here:

  • WordPress Dashboard s2Member General Options Email Configuration New User Email Configuration

There's also the Signup Confirmation email, which is the email sent to new Customers after they return from a successful signup (replace [Payment Gateway] with whatever payment gateway you're using; e.g., PayPal):

  • WordPress Dashboard s2Member [Payment Gateway] Options Signup Confirmation (Standard)
  • WordPress Dashboard s2Member [Payment Gateway] Options Signup Confirmation (Pro)

Any other emails that you see are most likely coming from WordPress itself. If you want to customize WordPress-related emails, I suggest posting a question on the WordPress Support Forum.

2015-01-16_18-17-34