You may think this is not important. You have a small business and you use a gmail, MSN or a yahoo account for your business. You use it because you are used to it. I was talking to a small business owner and he was confused why I thought it was important to have an email address that matches their domain name. I am not going to say get rid of your gmail or any other account, I am just saying that it is more professional to have an email that matches your domain name. An email address that is firstname.lastname@example.org looks more professional than a gmail that is email@example.com. A simple domain based email serves as an advertisement for your website. If you insist on using your gmail address, probably you could have a domain based email forwarded to your gmail address. If you have gone through the trouble of buying a domain and a website then why not use an email account that matches your domain. Some services do not accept gmail or other accounts. They require you to use your domain based email when creating a link with them or advertising with them.
More Traffic For Your Site
If your email address does not match your domain name, customers may think you are not committed to your business. They might think you are a spammer. Having an email that matches your domain name will also bring you traffic. For example you may pass your business card that has your domain based email or register at a site with a domain based email. The user or potential customer who receives your domain based email will surely visit your site.
A domain name email makes a small business more credible
A small business looks more professional when it has an email address matching its domain. Studies have shown that customers contacting the owner or employee whose official email address matches the domain feel more confident about a business.