Simply put, DKIM signing is a method to ensure that the emails you send are from trusted sources. It's an easy way to keep your email content intact throughout the delivery process, barring external threats from accessing and altering your emails. Proton Mail recommends DKIM activation for your domains.
Creating DKIM Record for Proton Mail
- Log in to your ProtonMail account
- Go to Settings > Organization > Custom domains > Actions > Review button > DKIM tab.
- You should now be able to see the 3 CNAME records that you will need to add to your domain’s DNS settings.
- Once you have added these records, ProtonMail will handle the rest for you. They will generate a new 2048-bit key rotated on a six-month basis that would be used to sign your emails.
Publishing the CNAME records for Proton Mail
After you get your CNAME records from Proton Mail:
- Login to your DNS provider’s management console as the admin
- Open to edit your DNS settings by clicking on Advanced Settings
- Create 3 CNAME records
- Copy and paste the hostnames and values for the records
- Save changes to your record and wait for 48-72 hours for your DNS to process these changes