So in this default situation, Outlook will check for updates once per hour.
To avoid this default one-hour situation, it is necessary to instruct Outlook to ignore the publisher’s recommendations (even though the publisher hasn’t made any explicit recommendations, the absence of a recommendation implies a 60-minute update cycle by default).
To do this, when adding the feed to Outlook, click the Advanced button and uncheck the box outlined in red in the screen shot above.
Note the yellow highlighted text indicates that the publisher has not specified an update policy.
Sometimes, the publishers’ update recommendations may be not fit for you, and you need the RSS Feeds update more frequently or less.