How to SPF Whitelist domain?

It is currently not possible to whitelist a domain by spf, it will be added in a future release.
However, whitelisting such large organizations, besides saving good emails against RBL blacklisting (which produces less false positives), makes spam emails not pass through the antispam filter (bayesian filter, AWL, content analysis,...), which may result in a higher amount of spam coming in. This can be tested right now by whitelisting those domains in the current whitelisting filter.