My friend Sughesh sent me an email from his company domain (small business). He sent me an email to my Gmail and Ananthapuri.com email ids. Unfortunately, his email went to Junk/Spam folder of both services. No doubt, his email was a decently one, personal email, no spam words!
As you know, most domains have their mail servers at mail.domainname.com. This could also be found out using an MX record query in the Domain Name Servers. I use the online tool MX Toolbox to find out whether a mail server IP address is blacklisted in any of the well known Spam blacklists. (Blacklist is a list of IP addresses of email servers of known spammers.)
While selecting a hosting service for your domain, check whether the MX IP addresses of the mail hosting service is blacklisted. Also check whether the mail server supports an open SMTP relay. That is, it is suggested to have the password required for relaying outgoing SMTP messages from the mail server. If there is no password protection, spammers can use your mail server to send spam, which will lead to blacklisting your mail IP address.
For smaller websites, shared web hosting service is used. Which means there will be hundreds or thousands of websites hosted in the same web server and all of them share the same CPU, RAM and IP address. The same will be applied for email service also. The same email server (the same IP address) is used for all of the domain emails. So, if some of the hosted businesses/persons misuse the email IP to send spam and junk emails, the IP could get blacklisted and affect everyone using the same mail server.
This should be one of the considerations for selecting a hosting service if you are planning to use your own email domain, hosted free, by your web hosting provider.
Another option for small businesses is to use Google Apps, which comes with Google’s standard Gmail interface. This service do not use the Mail servers of your hosting service.