Having your own email application would be hard to maintain. It requires expensive hardware and you have to also pay for storage. You’ll need a trained support team, and it will require ongoing backup and maintenance.
Therefore, off-site cloud based email applications are popular. With cloud based email applications, you don’t need to purchase your own hardware and set up your own servers or maintain the software. Instead you usually just pay a flat cost per user per month. Some personal email services don’t even have a cost associated.
Common off -site email applications include Microsot Office 365, and Google Mail (gmail).