The site I work on has a small wiki used by administrators for internal discussions. Over the years people have joined the group and then left. When they left, their accounts were blocked, but many have left the email notifications set in preferences. As these accounts age, the email addresses associated with them sometimes become invalid. This means emails sent to those addresses because of changes on watchlists bounce.
Right now the way we handle this problem is to reset the password for the user causing the bounces, login to the account and deselect all email notification options in preferences. However, it would be better if we could just reset the email preferences on all inactive accounts. Is there anyway of doing this other than resetting the password on each account (of which there are many)? We run 1.16.2 on this small wiki.