SPF
To authorize Combell to send emails on your behalf you will have to include it in your SPF record. The SPF record mechanisms used by Combell are shown below.
For Basic E-mail:
include:_spf.relay.mailprotect.be
For Exchange E-mail:
include:_spf.powermail.be
DKIM
For more information on enabling DKIM please contact Combell support team and they will be able to configure DKIM for you.
Create a free OnDMARC account to test your configuration.