Overview
A tracking domain is a secondary or subdomain name related to your original domain. It allows Apollo to redirect a tracking pixel added to emails to track opens, clicks, and unsubscribes.
Set up a custom tracking subdomain to identify how you're doing as a sender, keep your domain reputation safe, and as a result, improve the delivery rates for emails you send through Apollo. You can connect multiple custom tracking subdomains so that each user can select the subdomain that best fits their mailbox.
Apollo recommends 1 custom tracking subdomain per domain. For example, if you have 4 mailboxes:
- user1@domain.org
- user2@domain.org
- user1@trydomain.org
- user2@trydomain.org
Then Apollo recommends 2 custom tracking subdomains, 1 for each primary domain. Use the matching custom tracking subdomain for each mailbox within a primary domain.
Custom tracking subdomains are only one part of the equation. To reach your contact's inbox consistently, take a look at these email deliverability best practices and read chapter 7 of Apollo's book Outbound Sales. Follow the recommended sending limits and review the email deliverability checklist if you need a cheatsheet.
Check out the following sections to create, connect, and manage a new tracking subdomain.
Create a Custom Tracking Subdomain
To create a custom tracking subdomain, you need to first create a CNAME record. To do so, you need admin access to your domain management account.
Each domain provider has a different domain management interface. If you need help creating a CNAME record, visit the knowledge base for your domain provider and search for "create CNAME."
The following provides more details about the type of information you will need.
| Field | Definition | Field Information | Additional Notes |
|---|---|---|---|
| DNS Record Type | DNS Records include essential information about your domain or host. To set up a tracking subdomain, you need to select the record type: Canonical Name (CNAME). | CNAME | A CNAME record maps an alias name to a canonical domain name. |
| Host/Host Name/Name | Choose any name that is not directly related to your website. This name will become the subdomain in the URL that you create: subdomain.yourdomain.com | subdomainexample |
|
| Value/Data/Points To | The value you enter establishes the connection between your subdomain and the Apollo tracking servers. | Copy the custom value in the tracking subdomain settings in Apollo. 
|
Click Settings > Sales engagement > Tracking subdomains > + New Subdomain. Copy the value in blue from the Set up subdomain pop-up. |
| TTL | TTL is a technical term that refers to how often your subdomain information will be rechecked by relevant servers. | Leave as Default | You can leave this field as whatever value your domain provider uses by default. |
As an example, here's the layout from a GoDaddy account, one of the most popular providers. You need to add data into all of the same CNAME record fields. Once you create and save your CNAME record, it can take between 2-24 hours to fully propagate. 
If you're using other providers like Amazon Web Services (AWS) or Cpanel, check their help docs on subdomains to ensure you're reviewing the most up-to-date information specific to your use case.
Connect a Custom Subdomain to Apollo
To connect a custom subdomain to Apollo:
- Launch Apollo and click Settings > Sales engagement > Tracking Subdomains.
- Click New Subdomain.
- Enter the custom subdomain in the Domain text-box and click Create subdomain.
Did you know? You can connect multiple subdomains on Apollo. Every user with linked mailboxes can choose which connected subdomain to use for each mailbox. Apollo recommends that the subdomain match the domain of your linked mailbox. However, if that tracking subdomain is unhealthy, you should consider deleting the tracking subdomain and creating another one instead.
If you connect several tracking subdomains, Apollo will use the one set as default as the fallback when no option is chosen.
You have now connected your custom tracking subdomain. As a best practice, check your subdomain settings 24 hours after you finish the setup steps to ensure a healthy connection. When you have connected your CNAME record, the word healthy appears beside it. 
Set a Tracking Subdomain as Default
When users link a new mailbox, Apollo automatically uses the default tracking subdomain. You can still choose a different tracking subdomain if you want. To set a tracking subdomain as default:
- Click ... > Make Default beside the tracking subdomain.
You have now changed the default tracking subdomain.
View Tracking Statistics
To evaluate the performance of the emails you send and keep track of the open, click, and unsubscribe rates, you can access the Apollo tracking statistics. To view tracking statistics:
- Click ... beside the tracking subdomain. Then, click Check Stats.
Stats include key statistics related to the performance of the emails sent with the default tracking subdomain, like spamblock rate.
Few contacts open an email immediately after you send it. For this reason, Apollo tracking stats reflect data from the previous week and month rather than from the current week and month.
Deactivate a Tracking Subdomain
If your tracking subdomain is healthy, your recipients’ email servers aren't flagging your emails as spam. When you check email statistics in Apollo, you should see high open rates and low bounce rates. If your tracking subdomain is unhealthy, your recipients’ email servers are flagging your emails as spam.
You can expect that email servers will still occasionally flag your emails as spam. If you start to see a dramatic decrease in your open rates or an increase in spam-blocked emails, set up a new custom tracking subdomain. Then, deactivate the current tracking subdomain to remove it from your options and reset your deliverability. Remember to follow email deliverability best practices to avoid the spam filter. To deactivate a tracking subdomain:
- Click ... beside the tracking subdomain. Then, click Deactivate.
You have now deactivated a tracking subdomain.
Tracking links that utilize your custom tracking subdomain don't expire unless you delete the domain.
Troubleshooting Errors
If you receive an error message or see the word unhealthy beside your tracking subdomain after you connect it with Apollo, there are 2 main causes:
- CAA permission error
- CNAME error
CAA permission error
Apollo uses Let's Encrypt for tracking domains. If your team has set up a CAA record and you have not listed Let's Encrypt, please contact your DNS admin to update your CAA settings.
When you have given Let's Encrypt permission to generate certs, follow the steps in this article to reconnect your domain with Apollo.
CNAME error
There are several potential causes for CNAME errors. To fix the issue:
- Check for spelling mistakes.
- Confirm that you filled in all the required fields in your domain management account.
- If you've only just created a CNAME record, wait 24 hours. Then, try connecting your custom subdomain to Apollo again.
- If the problem persists, contact your domain provider's support team. Your account may have been deleted or deactivated on their end.
If you're still having issues connecting a custom subdomain to Apollo, support is only a message away! Reach out to Apollo support for more help.