Should I still try to reset NVRAM?
I've had four chats with Apple technicians, all to no avail. "Whoosh" seems to gone the way of the dodo. Any advice?
Try turning off 'Do Not Disturb' in System Preferences / Notifications - it worked for me
Alex
Finally, after weeks of trying to sort out the problem of 'soundlessly' sending emails, I have got it sorted. Thanks AlexR for your invaluable tip!
Finally, after weeks of trying to sort out the problem of 'soundlessly' sending emails,