In order to give convenience to Pepipost customers, The configured DNS records are automatically verified on the Pepipost dashboard once you click on "Check dns now" button under "view settings" tab next to your sender domain. If you have configured the DNS records within your DNS server, you just need to click on ‘Check DNS records now’ in order to verify the dns records configured.
Alternatively you can also use third party DNS validation services like https://www.whatsmydns.net/ or https://mxtoolbox.com/NetworkTools.aspx for more help.