Helping people with computers... one answer at a time.
Hotmail will keep your email for quite a while as long as you access it periodically. And if nothing goes wrong. Then you may have problems.
Do you know how long the item in the hotmail-inbox is preserved? In other words: when will the messages automatically be removes by MSN? Furthermore: does MSN keep a log of all mails received on the incoming mail server? The reason I ask is that I receive legally important mails which I want to be able to reproduce or proof its existence.
In my opinion, if you need it for legal purposes you should not, not, NOT be using Hotmail. Or any free email service, for that matter.
I have nothing against them, per se, they're fine services when used properly. But if you saw the constant stream of questions I get relating to lost accounts, lost email and worse, and the inconsistent or total lack of customer support at times, you'd understand why I take such a hard line on free email accounts.
I'll answer your question, but I'll also recommend some alternatives.
First, I have to say this: I am not a lawyer, and this is not legal advice. In fact, one of my pieces of advice below will be to confer with a lawyer for the requirements you might be facing in your situation and jurisdiction.
To the best of my knowledge most email services do not keep a log of incoming email. They deliver it, and then it's up to you to do with it what you will. The amount of data to keep a log of everything would be enormous. However, whether they do or do not, is also not something I would count on at all.
My current understanding is that Windows Live Hotmail will keep your mail:
As long as you keep the account open, and access it at least once a month.
As long as you do not exceed your storage limits.
As long as your account is not lost, compromised or stolen.
Of course, everything is subject to change without notice, but that's a fairly basic list for any provider.
The third point is what too many people stumble into. Accounts do get lost for a variety of reasons; everything from simply forgetting a password to actual account theft. When accounts are lost, everything is gone. All your mail is gone, your contacts and whatever else you had included with the account. (Often your friends and family start getting spammed as well.)
I hear about it every day.
Which is why I've been saying for years now: don't rely on any free email services as the only place to keep anything important.
Back. It. Up.
If you rely on Hotmail (or Gmail or Yahoo Mail or whatever mail) as the sole repository for important documents (apparently legally important documents in your case) you are playing with fire. You are at the mercy of that service, and if something should happen and you lose access you may have no recourse. None at all.
Back. It. Up.
My favorite way to back up services like Hotmail or Gmail is to configure a desktop email program to download email to your PC, where a) it's in your control, and b) you can back it up as you backup the rest of your computer.
But that's just one option.
In fact, if you have legal issues around which you're about to rely on email, I suggest you speak to an attorney. Hotmail may not be enough (especially if you lose access), downloading may not be enough, you may need to take additional steps (even, perhaps, printing the messages out). Again, your attorney can advise on what you need to do to make sure you're safe.
What I can tell you is that relying on free email services is not something I would feel safe doing, at all.