You think they may be in need so you contact them via email for the first time. does this work at all for attracting clients.
I wouldn't. First of all, it could (would) be considered as spam. But most would not open them. I wouldn't.
Although e-mail is a great way to communicate, it is NOT suggested as the first method of contact. As far as I am concerned, I wouldn't even open the mail.
Do you have a website for your business? If you do, you can set up Opt-in e-mail system and then stay in touch and build relationships with your prospects easily and at a very, very low cost.
Remember, there isn't any single one way to market that is best for every single business. Now, maintaining contact and developing your relationships is a different question. To start, you may want to look at flyers, postcards or even radio or other methods. Drive them to your website where you can collect e-mail.
Hope this helps! Good luck!