Can't delete auction mails

I placed bids in the latest auction and was outbid a few times

Now the auction has ended a long time ago but the "You have been outbid" mails are stuck in my inbox

The usual delete button does nothing and I tried any way I could think of to delete these mails but it just cannot be done

Mass delete a bunch of stuff and it says these mails are important and should be selected individually, but that does not work

Thank you for the report. This is a known issue, and I forwarded all the details to our Dev Team.

Same here -- kick the auction and make something usefull like a bulk-send of explorers