Sign and encrypt every email. Prove it came from you.

S/MIME certificates let you digitally sign outgoing emails — giving recipients cryptographic proof that every message is genuinely from you and hasn’t been tampered with in transit — and encrypt content so only the intended recipient can read it. Four validation levels cover every use case, from personal privacy to executive-level trust.

Anyone can send email claiming to be you

Email was not designed with authentication in mind. Without S/MIME, there is no cryptographic way for a recipient to know that an email actually came from the person or organization it claims to be from, hasn’t been modified since it was sent, or contains content that only the intended recipient can read.

S/MIME solves all three. It adds a tamper-evident digital signature to every outgoing message and optionally encrypts the content — all using a certificate issued and validated by SSL.com, a trusted, WebTrust-audited Certificate Authority.

Compare S/MIME Certificates

FeatureBasic S/MIMEIV S/MIMEOV S/MIMESponsor S/MIME
What is validatedEmail address onlyIndividual’s nameOrganization nameIndividual + organization
Best forPersonal email privacyProfessionalsOrganizations — functional addressesExecutives, key personnel
Digital signing
Email encryption
Individual name in signature
Organization name in signature
Prevents CEO/executive impersonation✗ No⚠ Partial⚠ Partial✓ Yes — strongest defense
Prevents corporate address impersonation✗ No✗ No✓ Yes✓ Yes
Trust level★ Entry★★ Professional★★ Corporate★★★ Maximum
CA/B Forum S/MIME BR compliant
Get startedBuy BasicBuy IVBuy OVBuy Sponsor

Find your S/MIME certificate in two questions

Still not sure? Consider what identity you need to prove: your email address only (Basic), yourself as an individual (IV), your organization (OV), or both (Sponsor). Our team can advise. Contact us

S/MIME Certificates at a glance

Basic S/MIME

For personal privacy

Digitally sign and encrypt email for a single address. No identifying information beyond your email address. Ideal for personal communications requiring privacy and integrity.

✓ Email address validation
✓ Digital signing
✓ Email encryption
✓ No additional info required

IV S/MIME

For verified professionals

Validates your first and last name in the digital signature. Builds professional credibility for client-facing communications. Ideal for lawyers, accountants, engineers, doctors, and notaries.

✓ Individual name validation
✓ Digital signing
✓ Email encryption
✓ Verified professional identity

OV S/MIME

For organizations

Validates your organization’s name. Prevents CEO identity fraud and corporate impersonation. Ideal for functional addresses: support@, billing@, admin@.

✓ Organization name validation
✓ Digital signing
✓ Email encryption
✓ Anti-fraud for org addresses

Sponsor S/MIME (IV + OV)

For executives & key personnel

Validates both individual and organizational identity. Maximum trust for executive communications. The strongest defense against sophisticated impersonation attacks.

✓ Individual + organization validation
✓ Digital signing
✓ Email encryption
✓ Prevents internal & external tampering

Common scenarios — which certificate applies?

ScenarioRecommended certificate
Individual encrypting personal email for privacyBasic S/MIME →
Solicitor signing client engagement lettersIV S/MIME →
Doctor signing patient communicationsIV S/MIME →
Company’s support@ or billing@ addressOV S/MIME →
HR department signing employment contractsOV S/MIME →
CEO or CFO signing board-level communicationsSponsor S/MIME →
Sales director sending proposals with company backingSponsor S/MIME →
Regulated industry employee (finance, healthcare, legal)Sponsor S/MIME → or IV depending on context
Automated system emails (no-reply@, notifications@)OV S/MIME →

What every S/MIME certificate requires

Valid email address

The certificate is bound to a specific email address. Each address requires its own certificate.

Identity documentation

IV and above require government-issued ID for individual validation. OV and above require business registration documentation. Sponsor requires both.

Email client compatibility

S/MIME is supported natively by Outlook, Apple Mail, Thunderbird, and most enterprise email clients. Gmail supports S/MIME on Google Workspace (Business/Enterprise plans).

CA/B Forum S/MIME BR compliance

All SSL.com S/MIME certificates are issued under the CA/Browser Forum S/MIME Baseline Requirements — the industry standard for S/MIME issuance.

An audited, compliant CA for enterprise and personal email trust

WebTrust for S/MIME BR (BDO)

Audited annually by BDO — SSL.com is a WebTrust-certified CA for S/MIME Baseline Requirements

CA/B Forum S/MIME BR compliance

All certificates issued under the CA/B Forum S/MIME Baseline Requirements — the global standard

Enterprise-grade PKI

Backed by SSL.com’s world-class PKI infrastructure, in continuous operation since 2002

Full-service support

From certificate selection to installation guidance and renewals — SSL.com supports the full lifecycle

API & automation

S/MIME certificates available via the SSL.com SWS API for enterprise bulk issuance and automation

Ready to sign and encrypt your email?

Choose your validation level and get started today. Not sure which certificate fits your situation? Our team will advise — at no cost.

We’d love your feedback

Take our survey and let us know your thoughts on your recent purchase.

Privacy Overview

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognizing you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.

For more information read our Cookie and privacy statement.

3rd Party Cookies

This website uses Google Analytics & Statcounter to collect anonymous information such as the number of visitors to the site, and the most popular pages.

Keeping these cookies enabled helps us to improve our website.

Show details