UTM parameters are labels at the end of a link (utm_source, utm_medium, utm_campaign) that tell an analytics tool where a visit came from. Add them to your links before you send; HawkOpen keeps them.
HawkOpen tracks a link only where your company has switched link tracking on and the recipient has consented to it; otherwise the link goes out unchanged and only your analytics tool sees the visit. Only https links are tracked; plain http links are left as they are. Expect the two tools to show different numbers: HawkOpen labels clicks by security scanners and link previews, while a website counts only visits that load the page.