Every published build is signed with an Apple Developer ID certificate and notarized by Apple before it appears here, and the notarization ticket is stapled into the disk image so it opens on a Mac that is offline. A build that does not pass Gatekeeper does not get a version number on this page.
The SHA-256 above is of the exact file we published. If what you downloaded hashes to something else, it did not come from us — write to support@humanrm.com and do not open it.
Updating is downloading the current build and replacing the copy in Applications. Your contacts, templates and send history live in your own user folder and are untouched by an update — and your licence key keeps working, because it is a signed claim rather than a record on a server we could lose.