Quote:
If you mail something and stamp it "non-machinable" ...
PS, IBFS: A careful reading of your predicate makes me wonder if you are stamping something "non-machinable" that would, in fact, be machinable ... a sleazy, under-handed, dishonest tactic that I thought of using, myself.
We should consider ikeyPikey's Dictum: "count on indifference to make a difference."
You should *not* expect that your non-machinable items will be in a separate mail stream, even if you hand them to a clerk. At some point, all of the mail might well be dumped into a common hopper, with the machine, itself, rejecting items that are well & truly non-machinable.
In that case, your machinable item, regardless of markings, would fly right thru the facer-canceller, and get shpritzed with that ugly black cloud that passes for a postmark nowadays.
Further, depending on which facer-canceller (etc) is in use at the end of that conveyer at that facility on that day for that mail stream, YMMV.
If you want the item to be treated as "non-machinable", you might take care to make sure that it is well & truly non-machinable.
Cheers,
/s/ ikeyPikey