We routinely run an automated script that analyses bounced emails, and if your email address has been found to bounce emails from our server, the routine will:-
a) delete all existing subscriptions
b) reset your subscription setting to "No email notification"
c) reset your PM notification to "No email notification"
Please ensure that your email address is up-to-date AND set your subscriptions to "No email notification" to prevent such deletion/reset in the future.