Skip to main content



DigiCert's publicly trusted S/MIME-related client certificates (Premium, Email Security Plus, Digital Signature Plus, and Client 1 S/MIME) are compliant with the new Baseline Requirements for the Issuance and Management of Publicly‐Trusted S/MIME Certificates.

However, DigiCert recommends moving to our new Secure Email S/MIME certificate products at your earliest convenience: Secure Email for Individual, Secure Email for Business, and Secure Email for Organization.


如果組織原則要求您加入憑證簽署要求 (CSR) 與您的用戶端憑證訂單,請建立您的 CSR。瞭解如何建立 CSR (憑證簽署要求)

如果組織原則要求您加入憑證簽署要求 (CSR) 與您的用戶端憑證訂單,請建立您的 CSR。瞭解如何建立 CSR (憑證簽署要求)

  • Provide a CSR now.

    You can only add a CSR when you place your request. After submitting your order, you cannot add or update a CSR.

    Client certificates support the following algorithms and key lengths:

    • RSA 2048, 3072, and 4096

    • ECC p-256 and p-384

    We only use the public key embedded in the CSR to create your certificate. All other fields in the CSR are ignored. Learn how to Create a CSR (Certificate Signing Request).

  • Provide a CSR later.

    After DigiCert processes your order and you complete the necessary email address validation, we send instructions to the email recipient for generating the CSR and certificate in their browser.

    For browser-generated certificates, we use an RSA algorithm, SHA256 signature hash, and a 2048-bit key length CSR. Learn how to Generate your client certificate using DigiCert's KeyGen tool.

Organization validation

Before we can issue a client certificate to an employee or company representative, DigiCert must validate the organization for SMIME – SMIME Organization Validation. Organization validation is valid for 825 days. See How we validate your organization.

Use one of the following options to validate your organization:

  • Prevalidate the organization

    CertCentral features an organization prevalidation process that allows you to validate your organization before ordering certificates. Completing the organization validation ahead of time allows for quicker certificate issuance. See Submit an organization for prevalidation.

  • Validate the organization as part of the order process

    If you add a new organization or an organization with expired S/MIME validation, DigiCert will complete the S/MIME organization validation as part of the order process.

Email address domain requirement

Before DigiCert can issue your client certificate, you must demonstrate control over the domains in the email addresses on the certificate order. In other words, if you add, you must complete the domain control validation (DCV) for the email address domain


Industry standards prevent Certificate Authorities (CAs), such as DigiCert, from issuing a secure email-type certificate until domain control validation is completed for the email address on the certificate.

Use one of the following domain validation options to demonstrate control over the email address domain:

  • Prevalidate the domain

    CertCentral features a domain prevalidation process that allows you to validate your domains before ordering certificates. See Domain prevalidation: Domain control validation (DCV) methods.

    Completing the domain validation ahead of time allows for quicker certificate issuance. You can also use any supported DCV method to complete the domain validation: Email, DNS CNAME, DNS TXT, and HTTP Practical Demonstration.

  • Validate the domain as part of the order process

    If you add an email address with a new domain or a domain with expired validation, you can complete the domain validation as part of the order process.

    When ordering a client certificate, you must use the Email DCV method to demonstrate control over the "unvalidated" email address domains on the order. Currently, this is the only supported DCV method for completing the domain validation during the order process.

    To validate the email domain, an email recipient follows the instructions in a confirmation email sent for the domain. The confirmation process consists of visiting the link provided and following the instructions on the page.

Organization attestation requirement

By adding a recipient name, your organization attests the individual is a valid employee or company representative and is included in official company registries. In other words, your organization is the registration authority for the individuals ordering these certificates. DigiCert only validates your organization, not the individuals.


  1. 在資訊看板功能表中,將滑鼠游標移到要求憑證上。然後在用戶端憑證下,選取您要訂購的用戶端憑證。

  2. 要求用戶端憑證頁面的憑證設定下,提供憑證詳細資料:

    1. 組織

      在下拉清單中,選取您要求 Client 憑證所要用於的組織。僅預先驗證的組織出現在下拉清單中。如果您找不到正在尋找的組織,請聯絡您的管理員。


    2. 簽署雜湊


    3. 有效期間

      選擇憑證的有效期間:1 年、2 年、3 年、自訂到期日或自訂長度。

  3. 訂單選項自動續訂下拉清單中,選取您想要多常自動續訂憑證。


  4. 根據憑證的要求,輸入收件者詳細資料


    1. 收件者名稱 (一般名稱)

      1. Select Email.

      2. Under Recipient email, enter the address you want to secure and use for the common name on the certificate.

    2. 收件者電子郵箱

      1. Select Name.

      2. Under Recipient name (Common name), enter the recipient's name.

      3. Under Recipient email, enter the address you want the certificate to secure.


    Only include email addresses with domains owned/controlled by your organization.

    • To include email addresses from public email service providers such as Gmail, Outlook, Yahoo, Hotmail, MSN, etc., order a Secure Email for Individual certificate.

    • To include an email address from a public email service provider you control, you must prevalidate the email address domain.

  5. 如果您正在使用 CSR 訂購您的憑證,請在收件者 CSR 方塊中上傳或貼上您的 CSR。

    You can add your CSR now or generate it in your browser after DigiCert processes your order, and we are ready to issue it.

    1. Generate CSR in the browser

      To generate the CSR and your certificate via the browser, select Generate CSR in the browser. For this option, we send instructions to the email recipient for using the DigiCert KeyGen tool to generate the CSR and certificate in their browser.

    2. Add CSR

      To include a CSR with your request, select I have my CSR. Upload or paste your CSR in the box.


      Your CSR must include the -----BEGIN NEW CERTIFICATE REQUEST----- and -----END NEW CERTIFICATE REQUEST----- tags.

  6. 若要新增更多用戶端憑證收件者,請按一下新增其他憑證連結,然後輸入收件者的收件者詳細資料

    Additional emails (optional)

    Enter the email addresses (comma separated) for the people you want to receive the certificate notification emails with information such as certificate issuance and certificate renewals.


  7. 選取付款方法


    1. 信用卡支付



    2. 以合約條款支付



    3. 帳戶餘額支付



      Note: Selecting the Deposit link takes you to another page inside your CertCentral account. Any information entered in the request form will not be saved.

  8. 憑證服務合約


  9. 按一下提交憑證要求

    By selecting Submit Request, you agree to the Master Service Agreement.


Before we can issue your certificate, these tasks must be completed:

  1. Demonstrate control over the domains on your order

    Complete the domain validation for the email address domains on the order (demonstrate control over the domain).

  2. Complete organization validation

    DigiCert must validate and authenticate your authority to order a certificate for the organization on your certificate order. To do this, we will call a verified phone number to speak with someone who represents you, the certificate requestor, such as the organization or technical contact.

    To get organization consent for your certificate order:

    1. Answer the organization/validation phone call (preferred method)*

      1. After you submit your certificate order, ensure that the organization contact, technical contact, and company receptionist know you’ve ordered a DigiCert client certificate.

      2.  Let them know DigiCert will call a verified phone number to speak with one of them to complete organization validation/authentication.

      3. This phone call usually takes place within 24 hours of the order being placed.

    2. Respond to the organization consent message

      1. If the DigiCert validation agent can’t reach someone who represents you at the verified phone number, they will leave a message with a call-back phone number and a verification code.

      2. Make sure that the organization or technical contact responds to the message and provides the verification code.

Getting your client certificate

  • Generate CSR in the browser

    After all email addresses are validated, a link will be sent to the first email address on the list so the recipient can generate the CSR and client certificate via the browser. See Generate your client certificate.

  • Included a CSR with your request

    If you submitted a CSR with your request, the client certificate will be attached to the "client certificate issued" email. You can also download a copy from your account.