Big companies like Google, Apple, Intel, etc. buy companies for access to their technology, for their patents and sometimes for their personnel. It is almost the normal thing for the purchased companies to be absorbed and their services to wound down. Google wants you to use nearly spam free G-Mail, not your own mail server or local ISP's mail service, so why would they continue offering a standalone anti-spam service? McAfee sells anti-spam as part of their security suites, why on earth would they sell the anti-spam service they've bought as an independent service under someone else's name?
Intel? Well who knows what goes on at Intel. My guess is that one management committee doesn't know what the other management committee is doing and haven't for decades now. Ditto Microsoft, IBM, etc.