When you change your website’s domains to a custom domain you can add an SPF record to your DNS settings for those domains so that your emails to the seller get delivered.
Do do this in goDaddy for example, you can navigate to the ‘My Domains’ section and then click on your domain and then click on the ‘DNS Zone File’ tab then under the ‘TXT (Text)’ section add a new record with the value…
v=spf1 include:mailSPF.smtp.com ?all
Example:
