It depends on the hosting service you are using. Some
shared hosting plans do allow you to share an SSL certificate on the server. The shared SSL certificate will not use your domain. Instead, it will use the server host name to allow an SSL connection without purchasing an SSL.
SSL certificates work only when there is a host name provided. Many shared hosting services install a valid
SSL certificate on all shared servers main host name. A connection made over that specific host name will allow the data to be encrypted. If you plan to use shared hosting, make sure you use a service provider that has shared certificates installed on all shared hosting servers. This can be used to encrypt
email service data without installing your own certificate.