In order to verify your domain name and to update SPF and DKIM properly, at your SMTP relay provider end, you need to add TXT, CNAME accordingly for your domain name. Depending on your domain host, this document explains about DNS update settings.
- Network Solutions
- Rackspace Email & Apps
- Inmotion Hosting
- Rackspace Cloud DNS
- Amazon Route 53
- cPanel DNS Update
After you have made DNS update at your hosting provider, you can verify DNS settings from Outside: https://www.whatsmydns.net/
Note: DNS updates take 24 to 48 to propagate completely, through out the internet.