Thank you for your reply. Yes, I am sure the emails are from disabled tasks. I had this issue when I prepared for a test upgrade on my HTPC with Windows 7 to Windows 10. On June 18 at 08:43, I first made an image of the regular installation and then made some adjustments to that installation as a preparation for the upgrade. One of these adjustments was disabling all scheduled tasks in Macrium so it would not conflict with the regular installation. After having made all adjustments I made another (full) image (June 18, 12:06). Because I did not have enough time to do the actual Windows 10 upgrade I restored the image of the regular installation. The next morning (June 19) I restored the full image of the adjusted Windows 7 installation to continue the upgrade and that is the moment and the installation I received the emails from, even though all scheduled tasks were disabled. I just (June 21) tested restoring the pre-upgrade image of the adjusted installation again and I immediately received the emails again.
I have attached a screenshot of the scheduled backups on the adjusted installation. What is noteworthy, now that I take a closer look, is that I only received emails for the missed tasks “Actueel dagelijks Beebox image (Win7)” and “Dagelijkse Discovery documentenbackup”, but not for “Mini HTPC bureaubladbackup” which was scheduled (but disabled) for Sunday the 18th at 20:05. Looking at the conditions for these schedules there are some differences between the various schedules in the Conditions (e.g. Run task as soon as possible after a schedules start is missed).
All scheduled tasks have “Send email notification on failure” and “Include skipped scheduled backups” enabled and this installation uses Macrium Task Scheduler.
Today I have also tried adding a one-time schedule for an image and immediately disabling it. For that new schedule no missed backup email was sent. I have no clue what exactly happens, but I can reproduce it by restoring an image.
Let me know if you need any further information.