I've just logged an email complaint with BT and am waiting the seven days for a reply. It's maddening as I rely on the reminder features of the calendar to help me work out what I'm supposed to be doing!
I'm pleased to say that all problems with my email and the calendar have now been fixed. For a day or so last week, the entire email system collapsed - calendar and all.
Rewinding events, I received an email reply to my complaint within the seven days notice period specified, saying they were taking the problem to the 'second level of engineering', whatever that means. Then I received a phone call from a customer service person who said my problems had been rectified but that he would call me again in a few days to check whether everything was satisfactory. When I returned to my email, everything was functioning normally, calendar included. It's been fine ever since, so I am pleased with the service and attention. I hope it doesn't happen again - it makes my hair stand on end!!