The problem is a bundle of registration activation emails being sent to members' email addresses instead of just to admin.
Fix is in hand now so if any turn up in your email inbox then just delete them.
I've stopped being 'attacked' now !
I found this very annoying as I have a loud tone for emails on my phone so I changed it for a quiet one, I can now revert back
Whilst good maintainece is the best prevention"If its not broken don't fix it."
Thanks to everyone for feedback here and by email: much appreciated.