The RSS feed is open to public, so is the errata page on the Portal (https://access.redhat.com/errata-search/). Subscribing to email notifications requires some sort of account, just like the mailing list did.

No, access is not restricted - here's a URL to their most recent security advisory in the OASIS open standard CSAF format:

https://access.redhat.com/security/data/csaf/v2/advisories/2...

It does not require any authentication to access.

Just run rss2email?

> RSS for anybody.

> The mailing list was open to all.

So what is the difference between "all" and "anybody" ?