To be even more explicit than tlrobinson's answer, they were trying to do long-term forwarding contracts before "falling back" to the painful "undeliver" model. The issue is that the USPS forwarding services are only meant to be used temporarily: they involve a cost to the USPS, and the longest contract you normally can obtain caps out at one year; by default I think you only get six months, in fact. They are really designed for two use cases: "I've moved permanently, but need some time to change all of my upstream addresses" and "I'm temporarily stationed at a different location, but will be back at my house within a month or two". ECM doesn't rely on the USPS in this fashion: your mail is delivered directly to them. I thereby would not be at all worried about the USPS getting angry at them: this article had simply not really highlighted the true point of contention involved.

What's really silly, frankly, about Outbox is that they clearly didn't do any due diligence before trying to start that company: somewhere around 2007/2008 is when I was first interested in getting a service like this for my mail. At the time, I thought "hey, maybe I could just forward my mail to this service". I saw you could forward mail, but it seemed like it was for temporary use. My response was not "well, let's see how long I can get away with this": I called the USPS, and within the hour of talking to various people, I was forwarded to the office of the Postmaster General. Now, I didn't talk to "the man himself", but I talked to one of his assistants. I seriously think I started this call path using 1-800-ASK-USPS, the phone number my friends and I would tell jokes to each other about how awesome it would be if the USPS were willing to answer entirely random questions ;P.

I explained my use case, and they explained to me that they were not able to offer this service for me, told me the reasons they did offer forwarding, explained why my use case did not fall into this, and was willing to brainstorm with me other options. I actually remember them suggesting hiring a personal assistant to undeliver my mail ;P. In the end, I finally decided (though I didn't get around to it for a long time later) to just "commit" and move all of my mail to ECM and forsake my address: frankly, this was the better option for me. I can see how this creates "market friction", though, for a service that is trying to "convert everyone" like Outbox. I thereby understand why a "hip" "web 2.0" company is instead going to look for something really really easy, like doing the mail forwarding path. What I don't understand is the "disruptive" attitude, however, towards getting what you want.

In this case, rather than call the USPS like I did as a mere user in 2008, they seemed to have just started signing up customers with mail forwarding for their new business idea. Well, that kind of sucks: the USPS doesn't want to offer that service. Now, some might think "those meanies don't want to do this" and paint a picture of corruption and bribery, implicating services like bulk mail as the cause of the problem, but if we try to think from the USPS's perspective for a moment: they are designed around this goal of moving mail to the address on the envelope... 99.99999% of their customers need that service, not a service that uses addresses as routing codes to redirect mail to some company. Their mail forwarding infrastructure is thereby expensive to use and maintain: why should Outbox get to use that service for free to make their business easier to operate?

So, yeah: I don't think anyone is concerned about the service ECM is offering. They seem to be offering a service that has been supported in some fashion for many decades now (again, it is reasonably equivalent to services that collected mail for people who lived in RVs, traveling the country without any kind of fixed or firm address), they aren't adding cost to the USPS in the way Outbox was, and they don't seem to have ever "made an enemy of the USPS" as Outbox seemed to consider core to their mission statement. I mean, even in their dying throws, they seem to feel like a Derek Khanna hatchet job against the Postmaster General is an appropriate next step... I will claim that this is a kind of "disruptive" attitude that makes it very difficult to actually "disrupt" anything ;P maybe there was some way to work with the USPS, maybe involving paying the USPS (as opposed to licensing stuff to the USPS, as if it had inherent value) would have worked for them? It sounds like they didn't even really try to go in that direction :/.