It happened that one of the times they put an unsubscribe link at the bottom, but if they didn't I just sent them to junk. (The way to market new infrastructure tooling is not to cold-email people that've worked here for a month.)
When a new employee joins the company, they will start getting texts to their personal phone number "from the CEO" asking them to handle an emergency by accessing a link or sending a file or whatever. It seems to happen right after they update LinkedIn with their new job. We also get email-based versions, but those are usually easy to block.
It's frequent enough now that we warm each person about it specifically as part of our initial welcome email and tell them to expect it.