BOAC,
I'm with green granite here. Yeah, I don't mind a bit of Microsoft bashing myself... but only in the appropriate circumstances.
It sounds like you are attempting to treat Hotmail as a commercial service, expecting the same support and reliability levels you would get from a paid service.
But as much as the internet and email has become a commodity (or even a "human right" if you ask some people), fact remains that the home user is not prepared to pay for the true cost of implementing systems and processes required to provide, maintain and support the IT infrastructure.
The rise of all these "Free" advertising reliant services in the past decade has done absolutely nothing apart from make the providers even more vicious about cost-cutting measures required in order to make their service even remotely commercially viable. Saying people like M$ and Google can afford it won't cut it, they quite rightly treat their services as seperate business units that are expected to be self-sufficient.
In terms of your specific problem, if you think about how long hotmail has been around, the size of their userbase and hence the volume of mails they have to process, you don't realise how much effort is required for them to constantly keep ahead of the spammers who are always pushing the boundaries. And because Hotmail are providing a free service, they are limited into what technologies can be deployed.
So there you go. I'm unsympathetic to people who expect mission critical reliability out of their IT whilst not wanting to pay anything (or close to nothing) for it.