How to Setup Custom Domain

Head to Settings > Mails & Domains and you will see "Add Sub-Domain" option.



Now add your sub-domain (do not add your root domain or else DNS check will fail)



you can use anything like a.yourdomain.com or b.yourdomain.com or track.yourdomain.com or fs.yourdomain.com.

Once done, click on continue.

Now head to your domain's DNS provider and let's assume that you are using track.yourdomain.com

Now:

Now checkback after sometime and then click on the check button, you should see a green check next to your domain that says "verified".



In general, DNS propagation takes few minutes but in some rare situations, your DNS propagation can take up to 48 hours.