Thank you, it helps ab but still tiresome. If I select the top level checkbox it does not select all, but only the ones that are visible on the page. So I have to repeat it more than 100 times :(
Hello Vitaly,
If your question is how you can do mass-clearing of IEM alartes then you should click on the "Alerts" icon --> Click "Full Screen" view button --> Select all alerts using the top level checkbox --> click delete:
I hope you find this information useful.