We've had a complaint from a technically literate, helpful, friendly member of the list that they are receiving feedback loop reports from one of the 500lb gorilla freemail providers.
These show that a subscriber to this list is clicking "this is spam" on list messages.
Whilst this function might have the same effect as "delete" it also cascades a bunch of actions behind the scenes which can result in innocent third parties being blacklisted.
If those third parties are helpful types then the outcome hurts the whole list.
On behalf of the list's moderation team I say:
DON'T DO IT. IT'S RUDE AND UNPRODUCTIVE.
Save the spam button for spam. If you don't want list mail any more, unsubscribe.
If we receive any further complaints we will unsubscribe the offending account without further warning.