> That's a rather glib and obtuse way to put it.
Glib, yes. Obtuse? less so.
>I'm an Amazon customer. If Amazon can't reach my gmail address because Google started using some third party filtering service, what exactly would you expect me to do?
If your free email address doesn't receive mail you want, I expect you might move to a different mail service. I think that if you want anything but automated support out of a free service, you are expecting far too much. Because you still seem to think sticking with your free email provider is the only reasonable course of action, I can only assume that said free provider is meeting your needs; that the automated support is good enough and that you don't mind the odd false positive.
Sure, if you want service, you are going to have to pay a few dollars, but there are plenty of spamfiltering services that are fairly cheap that do have a real person who will fix it if you tell them you aren't getting legitimate mail.
In reality, users consider "legitimate" newsletters to be spam... spending a bunch of time digging through the "legitimate sender" settings to get the mail you want and not the "legitimate newsletters" is often so much work that users just mark the newsletters as spam, and hope their provider will figure it out. Of course, this works really badly when it comes to reputation systems, as the billing stuff and the "newsletters" often come from the same server.
(really, if you must send "newsletters" in addition to your billing, you should do them from a different mailserver and different email address.)