How to Set Up DKIM for Proton Mail

Enable DKIM for Proton Mail by publishing three CNAME records for the protonmail, protonmail2, and protonmail3 selectors.

Quick Answer — The Record You Need

Record Type

CNAME

Host / Name

protonmail._domainkey

Value

protonmail.domainkey.dxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.domains.proton.ch

Proton Mail provides three CNAME records with selectors protonmail, protonmail2, and protonmail3. Values are unique to your domain.

Step-by-Step Setup

Log in to Proton Mail

Go to mail.proton.me and sign in.

Navigate to domain settings

Go to Settings > All settings > Proton Mail > Domain names. Select your domain.

View DKIM records

Proton Mail displays three CNAME records for DKIM in the domain setup wizard.

Add all three CNAME records

Create the three CNAME records in your DNS provider.

protonmail._domainkey.yourdomain.com   CNAME  protonmail.domainkey.dxxx...domains.proton.ch
protonmail2._domainkey.yourdomain.com  CNAME  protonmail2.domainkey.dxxx...domains.proton.ch
protonmail3._domainkey.yourdomain.com  CNAME  protonmail3.domainkey.dxxx...domains.proton.ch

Verify in Proton Mail

Click "Verify" in Proton Mail. The platform checks all three CNAME records.

Common Gotchas

Proton Mail requires three CNAME records (protonmail, protonmail2, protonmail3). All three are needed for key rotation.
The CNAME values contain a unique identifier for your domain. Copy them exactly from Proton Mail settings.
CNAME target domains point to domains.proton.ch. This is the correct Proton infrastructure domain.

Verify Your Setup

After adding your DNS records, use our free DKIM checker to verify everything is configured correctly. DNS changes typically propagate within minutes, but can take up to 48 hours.

Frequently Asked Questions

What DKIM selectors does Proton Mail use?

Proton Mail uses protonmail, protonmail2, and protonmail3 as DKIM selectors. All three are published as CNAME records.

Why does Proton Mail need three DKIM records?

Three selectors enable seamless DKIM key rotation. Proton can rotate keys without any downtime or DNS changes needed from you.

Does Proton Mail rotate DKIM keys automatically?

Yes. The CNAME-based setup allows Proton to manage key rotation on their infrastructure.