Mail action

Hi,
Very strange, your error says:

Rule ‘Test Mail’: An error occurred during the script execution: The name ‘OfflineThings’ cannot be resolved to an item or type.

But your rule doesn’t mention OfflineThings.

Also, your wildcards (import org.openhab.core.library.types.*) are still there.

Are you sure you use sendmail in the right way? See documentation.
I would expect something like:

sendMail("youremailadres@something.com", "Item goes offline!", "Something in the body of the mail")

I think this is also an interesting read for you:
Design Pattern: Working with Groups in Rules.
In summary:

  • Put all your items (Item Sk1_power_reachable, Item s009_power_reachable) in a group (e.g. gPowerStuff);
  • Change your trigger to “when gPowerStuff changed to…”. This makes it much easier;
  • You can refer to your triggered item as “gPowerStuff.members.sortBy[lastUpdate].last.state.toString”. Again, see the Design Pattern for details.