I am using postmark for sending emails from a domain hosted at digitalocean.
How can I setup the SPF and DKIM records. I did as postmark support said me to but I am not able to get it verified.
Without know more information, it's difficult to help. To troubleshooting an issue with SPF and DKIM records, a good first step is to use the dig command to verify that the records being returned match the values provided by Postmark for you.
- dig example.com TXT
Postmark does provide a helpful article that should walk you through the process of adding DKIM and SPF records in the DigitalOcean DNS panel: