Rosicrucian Digest is a publication of AMORC, published continuously from 1915.
It is sent to members via correspondence, but it is also available to the general public.
You can read Rosicrucian Digest issues at the web site of the English Grand Lodge of the Americas.
It is not the same as Rosicrucian Forum, which is another publication of AMORC available only to members.
In the past Rosicrucian Digest was named Mystic Triangle.