The full public archive of the mass alerts we email Senserva Watch members: the date each one went out, the CVEs and KBs it named, and the text exactly as members received it. Free to read, no sign-in, and the same log is a JSON feed you can consume.
What was sent, never to whom. Recipients are not in the log and not in the feed. Every CVE and KB below links to our own page for it where we hold one, and to Microsoft where we do not.
The archive is published as JSON on the same schedule, so you can pull it into your own tooling. It carries the send date, the CVE and KB ids, whether we hold a page for each one, and the alert text.
More free feeds, including the ranked hot list and the Patch Tuesday calendar, are on the feeds and API page. The live trackers are the Microsoft patch tracker and the non-Microsoft exploited CVE tracker.