You can use an extern SMTP service like G suite to relay emails.
1. Log into your cPanel account.
2. In the "Domains" section, click on "Zone Editor" Icon.3. In the domains list, select the domain appropriate domain and click in "MX Record"
4. In the next screen fill in the SMTP server address that you want to use.
5. Next, you will have to change the type of outgoing mail server, again on "Domains" section, click on "Email Routing". Then,select the domain and change your configuration option to: "Remote Mail Exchanger".Congratulations! Your MX records are now configured to point to another SMTP server.
Remember those changes to MX records may take up to 48 hours to take effect.