S/MIME certificates

Protect your email accounts and messages

Sender confirmation and message encryption with S/MIME certificates

S/MIME Certificates enable anyone to send signed and encrypted emails – ensuring their confidentiality and integrity.

Actalis offers S/MIME certificates that are compatible with all the main S/MIME-compliant email applications, including Microsoft Outlook, Mozilla Thunderbird, Exchange, Gmail, and many others. We offer a free version of the certificate, valid for individual email addresses, as well as an enhanced corporate version for use by organisations.

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Actalis S/MIME Certificates: key benefits

Thanks to our S/MIME certificates, organisations can rest easy knowing their emails are truly secure, irrespective of the features of the email service they use.

  • Confidentiality: all messages are encrypted and can only be decrypted by the recipient. This prevents any data from being intercepted by malicious third parties.
  • Authenticity and integrity: all messages are digitally signed. This enables recipients to check whether the correct sender is displayed and verify that the message hasn’t been altered.
  • Brand trust: by using Actalis’ S/MIME certificates, organisations can demonstrate their trustworthiness to customers and partners.
The benefits of Actalis S/MIME Certificates

Actalis S/MIME certificate solutions

Free version: perfect for testing the effectiveness of S/MIME Certificates, or for personal use


To get started with S/MIME certificates, all you need is an email address! Our free S/MIME certificates contain just the owner's email address and are valid for year. They can be requested at any time, with no third-party intervention required.

Apply for a free S/MIME certificate

Corporate plan: Enhance confidentiality and prove authenticity with S/MIME certificates for your organisation


Our corporate S/MIME certificates include the name, organisation and email address of the sender. They’re valid for three years, and enable customers to configure the technical signature method to their own needs (e.g. specific regulatory frameworks).

Get corporate S/MIME certificates

Talk to an expert

S/MIME certificates are an important tool for securing your email communications. Don’t hesitate to get in touch if you’d like to learn more, or need help implementing a custom solution.

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More details

S/MIME certificates are issued using a self-provisioning platform by completing the following forms:

Free S/MIME certificates can be requested at any time, requiring no preparation by third parties.

For Corporate S/MIME Certificates, however, certain preliminary steps are required from the customer (namely, the company/body of the users involved):   

  1. Defined user list – the customer informs Actalis, using an agreed secure channel, of the list of users to whom certificates should be issued.
  2. Voucher created – The Actalis Delivery team creates a list on the Certification Authority and generates a voucher which it thereby communicates to the customer.
  3. Voucher distributed – The customer communicates the voucher code to the users for whom it has requested the certificate.
  4. Certificates generated – Individual users access the online request form, where they can obtain the certificate by entering the voucher details and their email address.
When submitting the online request form, the user is also required to enter a “challenge”, received via email, which enables the CA to verify that the user is indeed the owner of the email address.

When the request form has been correctly filled in and submitted, the user receives the certificate in real-time in .PFX (PKCS#12) file format, also containing the private key; the password for the .PFX file is displayed on the screen.

Finally, the user downloads the .PFX file and imports it to its own email client, after which it can start sending signed or encrypted emails straight away.
  • Microsoft Outlook
  • Windows Live Mail
  • Mail for Windows 10
  • Outlook Web Access + S/MIME Control
  • Apple Mail (OS X 10.6+, iOS 8+)
  • Mozilla Thunderbird v52 or later
  • Gnome Evolution v3.18 or later
  • SeaMonkey v2.46 or later
  • eM Client
  • The Bat!
  • CipherMail (for Android)
  • R2Mail2 (for Android)
  • Nine (for Android)
  • Fossa Guard Pro