False email report from powered off computer

Hello!

My computer protected by Trend Micro Antivirus+ was switched off between 11th and 17th of May. On 15th of May an email from Trend Micro came to my mail box registered for this subscription. It alerted that I had to setup "Folder Shield".

However this folder protection was configured on the first day when I installed Antivirus+ and purchased a license for it, it was setup on 4th of May, so obviously long before 11th or 15th of May.

So can you explain why I'm receiving such false reporting email and I'm also interested why that email came about powered off computer?