Mail list of 9000

My suggestion is to work with a copywriter in any message you send to that list. That is my 2 cents. A good copywriter is like having a man with golden words.

Carefully...

I would put a disclaimer there for all to see,

Something like "you are getting this email because you purchased from 123company in the past".

And then have a prominent unsubscribe link for them to make use of instead of the dreaded "spam" button.

This is only my thoughts, so tell your friend to tread carefully.

Baz

Definitely sound advice but I was thinking more in terms of how to send to the list safely. They contacted Constant Contact and I think one other place and both places said they couldn't use their services to send to the list for lack of dbl opt-in and not havign an express marketing disclaimer upon giving their email when buying goods.

My 2 cents added here-

I'm a subscriber of Anik Singal. Anik sends me offers with his affiliate links. But the best one I love is that he sometimes sends wonderful free gifts. Why don't you start with sending free gifts like these? They'll be more than happy. What do you think?

You don't have that many options really.
One company who would probably let you split the list and do perhaps 3 separate mailings is Email Marketing Services by VerticalResponse | Unbelievably Simple, Incredibly Effective - they seem a bit more tolerant when it comes to larger non opt-in lists. But it will cost you about 10 cents per name.

Or, you could take a chance by setting up a hosting account and installing a free mailing application. You'd need to limit the number of emails per minute to stay within the hosts TOC, which most mail apps will allow you to do. Personally I'd set the list to go out over a longer period, perhaps 2-3 weeks, so instead of getting hit with an instant deluge of complaints they'll trickle in at a slower and more manageable rate.
But be careful if you go down the self-hosted route, as you'll really want to try and stay within the hosts TOC.

Beyond that there are a few desktop email applications that you could use. Just Google that term and you'll find a bunch.
But you stand a chance of your ISP shutting you down. Of course there are ways to get around that too, but I'm starting to sound like a spammer and I don't want to go there!!

Your list is a hot potato so you'll need to wear oven gloves to handle it.

This is a risky list. Whatever you do, whether you go down the AR route or get your own mailserver, introduce yourself in the first mail. Remind them of why/how they got on your list. Doing this will reduce the spam complaint rate and the unsubscribe rate. And definitely offer them some incentive for being/staying on the list, like a discount off their next purchase (your friend's running a physical goods company, right?), etc.