There are many ways to set up a Submit button, but the way you are describing is using the "Email Submit" button in LC Designer. You can change the email address here:
If on the other hand you have used a Regular Button and changed the type to Submit, then you would access the email via the Submit tab:
That deals with the LiveCycle side of things.
The next step is if you had Reader Enabled the form in Acrobat. What happens next depends on the version of Acrobat you have, but if it is Acrobat version 8 or 7, then the step to Reader Enable the form is to Distribute the form via the Form menu. See this example/summary with screen shots: http://assure.ly/etkFNU .
If you have made a mistake during this process, then you may have affected your ID in Acrobat preferences. I can't do a screenshot for Acrobat version 8 or below, But if you have a look in Preferences (from the Edit menu) and go to the Identity tab, check your email address there:
This is Acrobat X:
Hope that helps,