To allow Suresupport to send emails on your behalf, you will have to add them to your SPF record. The SPF mechanism used by Suresupport is shown below.

include:SERVERNAME.smtp-spf.sureserver.com

Where SERVERNAME would be the hostname of the particiular server your hosting account is on.

You can automate this process via the DNS Manager section of your hosting control panel. Just use the Enable button under Mail Protection which will automatically add the SPF text record in the DNS.
​
For more information please click the button below.

To enable DKIM protection for Suresupport, you need to click on the Enable button in the Mail Protection subsection in your DNS Manager section of your control panel.
​

For more information please click the button below.

Create a free OnDMARC account to test your configuration.