If You Are In Business, Act Like You Are In Business
Customers and suppliers expect that if you hold yourself out as being in business that you act like you are in business.
That means that you have a domain name.
It means that you use email with an email address that uses that domain name.
Even when you are starting up, if you are contacting potential suppliers, you should have a web site. All that has to be is a simple, one page product blog. That is simple to set up and free if you use the right web host.
You should set these up as soon as you decide to go into business and BEFORE you contact potential suppliers. You will be taken seriously and not as just another one of those thousands of people trying to get wholesale prices on products for personal use.
There are technical considerations also. Your email will not be filtered or censored. You will get all your commercial mail. (Read about filtering here.) And you are likely to find it easier to download commercial files.
Plus the earlier the search engines find your product blog, the faster they index you.
And it is absolutely critical for your customers. They are bombarded by mail from fly by night operators constantly. You have to show that you are a serious, professional who pays attention to detail.
Here are recommendations.
Get a domain name and web hosting company. You can get a free domain name at each of these along with hosting. And you can set up your email account. Of course, there are others. Web Hosts
Set up a product blog. The blog comes free with each of the hosting companies above. Information about a product blog is at Product Blog
Taking these steps will make people take you seriously.
In short, there are unwritten rules for doing business on the web. These are basic rules. Failure to follow these basic rules is the first step to failure.