Why would we need SMTP2GO?
Every person, and every business, needs a reliable outgoing email service for sending emails. SMTP services offered by webhosts and ISPs are being discontinued, or greatly restricted. They don’t want to run them in the first place, and put the minimum possible amount of resources into their maintenance. When things go bad, you’ll likely be left high and dry, trying to get answers from support staff reading from scripts.
Aside from low quality webhost/ISP services, you theoretically could run your own email servers. However, bear in mind that email delivery is a complex, specialized, and constantly evolving field that really does take years of experience and hours of time every week.