As you know Manager sends email to foreign email addresses and also records it to an email address as setup under email. Coming to think about it with the newish Email Tab that may not be necessary or relevant as Lubos suggested.
From a business perspective the Payslip Email ought to be private to the recipient and to the Payroll User.
I have deselected and removed the Email TAB from users but the idea or option above to have Payslips when emailed from manager not be included in the “ Send a copy of every email to this address ” will still need to get attention.
I have made certain that users do not have the Attachments Tab enabled as well because once again in there all Payslip and IRD data / communication is revealed as well.