How to Improve Email Deliverability with a Custom Tracking Subdomain

When sending emails through Crono, the system may include:

• a tracking pixel to monitor opens

• a redirect link to track clicks

These are essential to measure engagement, but some email providers (such as Outlook and Gmail) may flag tracked links as suspicious, showing warnings like:

“Anti-spam service has detected a potential phishing attempt from api.crono.one”

This can negatively affect deliverability and how recipients perceive your email.

The solution: use a custom tracking domain

To avoid these warnings, you can set up a custom tracking domain.

This replaces Crono’s default link (api.crono.one) with a domain that belongs to your company, for example: crono.yourcompany.com

Using your own domain increases trust, improves deliverability, and reduces spam/phishing alerts.

How to set up your custom domain

To enable a custom tracking domain, you must have access to your company DNS settings.

1. Create a CNAME record

In your domain DNS panel, create a CNAME record for the subdomain you want to use.

Example:

• Type: CNAME

• Name: crono.yourcompany.com

• Value: api.crono.one

2. Notify Crono

Once the CNAME is created, notify our team.

We will:

• generate an HTTPS certificate for your subdomain

• provide an additional DNS record needed to validate the certificate

3. Add the verification record

Add the second DNS CNAME record we send you to complete the SSL validation.

This ensures your custom tracking domain is secure and trusted by email providers.

4. Activation

Once the SSL validation is completed, our team will activate your custom tracking domain.

From this moment:

• all tracking links and pixels will use your domain

• phishing warnings should no longer appear

Need assistance?

If your technical or IT team needs help with DNS configuration, contact us. We can guide you through the steps or provide a detailed setup document.