Yes, wastingtime, you are indeed correct to point this out. This is one of the many contradictory provisions eBay put before us in the rollout of the ESE. These pasteboard envelopes, one of which I have in hand as I type this, are normally considered a non-machinable mailer, used to avoid flexing of the product, rigid, and not flexible. I will grant you that it is actually flexible to a point. The question is, what point? I will load one up with a postcard soon and see if the USPS accepts it and if it can successfully traverse the 9-inch circumference scanners at 100 miles per hour. Nowhere else in eBay documentation that I have read suggests that a rigid pasteboard mailer is specifically OK'd for ESE, and it's strange that it's only specified in a FAQ. And the USPS seems to be considering rigid mailers nonmachinable.
Regardless, have you found them to work for ESE?
Afterthought: The 5x7 mailer I'm looking at here is definitely too stiff to meet the machineability criteria, which I will ask about at the post office before trying to mail one. It looks to me that it would either be harhly creased, destroyed, or rejected by the machine. Surprisingly it's considerably stiffer than the 6x8's I get from another source.
