The benefits of having company email addresses are better perception, a trustworthy appearance, better compliance and security, better spam filtering, and a better backup for emails. These factors make it worthwhile for businesses to spend money on company email addresses rather than employees using free personal email addresses.
One benefit of having company email addresses is that it improves the perception of the company. Many users have personal email addresses with colorful names that will look less professional than a company email address featuring only their first name, last name, and a domain name with the company's name. The company domain name itself can make customers likelier to trust a business they see as established.
The company email addresses also make it easy for the customers to locate the company website and research the company, making it seem more legitimate in their eyes.
Company email addresses are also less likely to fall prey to their information being hacked than free email services are, and this heightened security can make it easier for the company to comply with any local, state, or federal compliance requirements.
Many customers' emails will have spam filters that are less likely to route email from a professional domain name into the spam folder than emails from popular email services, ensuring important messages get to whom they are sent.
Finally, it is easier for a company to backup email records of their own emails in the event that the information does end up hacked or otherwise lost.