Email & Brand Trust · S/MIME

S/MIME Certificates

Digitally sign and end-to-end encrypt email — four assurance tiers, from quick personal use to enterprise compliance.

S/MIME is the industry standard for signing and encrypting email. Signed messages get a verified-sender indicator; encrypted messages are unreadable even if intercepted in transit. The four tiers below differ in how much identity is verified before issuance — from email-only validation up to dual person-plus-organization verification.

✓ Sign + encrypt email ✓ Outlook, Apple Mail, Thunderbird ✓ End-to-end encryption ✓ Aligned with CA/B Forum S/MIME BR

Choose the S/MIME tier that matches your assurance level

From entry-level email validation to dual person + organization vetting.

Email validated

Basic S/MIME

Entry-level S/MIME: validates the email address, issued in minutes.

Email-address validation
Issued in minutes
Sign + encrypt
Affordable

Affordable Learn more →

IV · Individual

IV S/MIME

Verified legal identity — your real name in every signed message.

Government-ID validation
Legal name in signature
1–3 day issuance
Strong personal identity

Identity-grade Learn more →

OV · Organization

OV S/MIME

Verified company identity — for role and department mailboxes.

Business identity validation
Company in signature
Role mailbox friendly
Anti-spoofing for business email

Business-grade Learn more →

IV+OV · Sponsor

Sponsor S/MIME

Strongest tier — verified person AND verified company. CA/B Forum aligned.

Person + organization verified
Aligned with S/MIME BR
Strongest commercial tier
Built for compliance

Enterprise Learn more →

S/MIME tiers compared

	Basic	IV	OV	Sponsor
Validates	Email address	Individual identity	Organization	Individual + organization
Signature shows	Email	Legal name	Company name	Name + company
Issued in	Minutes	1–3 days	1–3 days	1–5 days
For	Personal email	Regulated individuals	Role mailboxes	Enterprise / compliance

Frequently asked questions

What does S/MIME actually do?

Two things: cryptographically signs outbound messages so recipients can verify the sender, and end-to-end encrypts messages so only the intended recipient can read them.

Which mail clients support S/MIME?

Outlook (desktop and web), Apple Mail (macOS and iOS), Thunderbird, eM Client, and most enterprise mail platforms. Webmail services like Gmail typically require workarounds through desktop clients.

Which tier should I pick?

Personal use: Basic. Independent professional: IV. Business role mailbox (support@, billing@): OV. Enterprise employee in a regulated industry: Sponsor (IV+OV).

What changed with the CA/B Forum S/MIME Baseline Requirements?

The CA/Browser Forum formalized S/MIME tiers (Mailbox-Validated, Individual-Validated, Organization-Validated, Sponsor-Validated) with explicit requirements. Sponsor S/MIME is the highest tier and increasingly the compliance target.

Can both sender and recipient encrypt without S/MIME on both sides?

For encryption both parties need certificates. Signing works the moment you have yours — recipients see the verified-sender indicator without having S/MIME themselves.