>The USPS inserts vast amounts of advertising into my letterbox, and (unlike in most countries) there's no way to opt out.

They don't insert it inside an envelope someone else sends you.

"Every Door Direct Mail" blurs the line a bit. https://www.usps.com/business/every-door-direct-mail.htm

Not really. If I send you a (for example) Christmas card in an envelope - there is no way the USPS will insert an advertisement in the card.

USPS doesn't insert the ad into the post, they *deliver* an ad in the post. They aren't making it and inserting it - like what MS is doing.

I’m not a fan of USPS but I agree this is not their fault. In fact they’re not allowed to “filter” the mails.

USPS inserted this link into their Informed Delivery email to me last week:

https://pugetsoundraffle.com/overview?usps_mid=106545&usps_s...

Absolutely no excuse there for USPS to be sending me spam links when informed delivery was supposed to be a way to get a picture of your coming mail.