I'm using rss2email with multiple categories on a dedicated IMAP account + sieve to organize into IMAP folders (using + email separator) and discard / filter topics I don't care about.
I use my own email server (Postfix + Dovecot + OpenLDAP + OpenDKIM + DMARC + Spamassassin) and have SOGo on top of it for calendar / todo / contacts sync.