1000 FAQs, 500 tutorials and explanatory videos. Here, there are only solutions!
WorkSpace: deleting messages which are struck though (crossed out)
In order to permanently delete the tracked email messages that appear in your email software or WorkSpace:
Go to Edit -> Purge the deleted messages.
Go to the MAILBOX menu -> Clear the deleted elements.
They will also disappear from your Webmail.
Link to this FAQ: