Choose a Certificate Authority (CA): Select a reputable CA that offers S/MIME certificates.
Generate a Certificate Signing Request (CSR): Generate a CSR from your email client or during the configuration of your new certificate.
Submit Your Application: Fill out the configuration form to request the new Certificate, attaching your CSR if necessary.
Verify Your Identity: The CA will require you to verify your identity and email address through documents or an online verification process.
Install Your Certificate: Once verified, you'll receive your certificate. Follow the CA's instructions to install it on your email client.
Remember, the process can vary slightly between CAs and email clients.