Received this morning:

This e-mail has been sent to you by Open Diary to let you know that your
diary [...] has been inactive for over a year. As a result, the diary is about to be
permanently removed from the system.

If you would like to preserve your diary, all you have to do is come back
to Open Diary, log into your diary, and update it. This will remove it
from the inactive list.

'tis the end of an era.