What HawkOpen offers, so you can compare: a browser extension for Gmail, Outlook on the web and Yahoo Mail; a classification and rule code for every open and click; tracking only after your company’s owner or an admin switches it on and only for recipients whose consent is recorded, each in a separate tracked copy; a free plan with no time limit; and a notice about tracking in every tracked email, with a link where the recipient can turn it off.
What HawkOpen does not offer: an Outlook desktop add-in, mobile apps, automated email sequences, ready-made CRM integrations, and document and e-signature features in production (they are a preview until file scanning is on). If you need those, another tool may suit you better.
Where rules that require consent apply, tracking may start only after that consent has been obtained. The link in the message lets the recipient withdraw consent later.