This is probably the most authoritative group available for Advaita philosophy in the tradition of Shankara. Much of the material posted can be very academically biased however and is often related to Hindu ritualistic aspects. Naïve posts or observations not strictly within the guidelines for the list are not well tolerated.
This is the group that I would most recommend. It exists to discuss any Advaita-related topic, on any level. Though it takes the teachings of Shankara as its baseline, followers of Direct Path methods are not at all frowned upon! There are 2075 members as of September 2009. Many of its senior members are very knowledgeable and able to comment learnedly on all topics. There are also numbers of relative newcomers, both from traditional Indian backgrounds and from other Western traditions. Questions from newcomers to the philosophy are always treated with respect and never answered patronizingly. There are clear guidelines for behavior in the group and intervention by the moderators is very rare. Disrespect or posts that are outside of the subject matter are not tolerated, however. In the 11 years of my membership there have been many excellent discussions. There are also ongoing expositions, with discussion from time to time, on topics such as the Bhagavad Gita.
Their homepage contains general information and an invitation to join.
NonDualitySalon is a long-established group. It is run by Jerry Katz, who also has one of the largest web sites on Non-duality, listed on the Advaita-Related page.
I left this group in October 2004 after a prolonged period of heated exchanges between several members. Accordingly I do not know how it is going at present. With 142 members in August 2005, this
could certainly be worth trying again.
There is intentionally not a lot of discussion on this list, which exists primarily for members to post extracts and quotations from the Sages. Principal amongst the sources are Ramana Maharshi and Nisargadatta Maharaj, though any Advaita material (actual or effective) is acceptable. This list provides an excellent opportunity to discover ideas, and ways of expression, that strike a chord. 359 members at October 2009.
Satsangh This list is dedicated to Sri
Ramana and the pure teachings of the Self as
taught in Advaita Vedanta and supports all
the preliminary practices of yoga and meditation
in the context of teachings of Ahimsa, the
philosophy of non-violence. 1262 members as at October 2009. There is also a
NDhighlights provides daily posts - the editors are Jerry Katz, Gloria Lee, and Mark Otter. There are no discussions on the material. The extracts that are posted draw on other sources on the Internet, including many non-dual egroups and websites. News articles, discourses, poetry and random information that has caught the interest of the poster - anything may appear. If you do not know where to look for inspiration, something here is likely to appeal eventually. 1852 members at October 2009.
There are 83 E-groups (Oct 2009) with reference to Ramana Maharshi at Yahoo alone. The largest one is Italian and Harsha Satsangh and Million Paths have already been mentioned. Of the remainder, the only one I have personally had any dealings with was Ramana_Maharshi (296 members). There is a ‘silent group’ SriRamana (173 members), which simply emails members with a short quotation from Ramana each day.
Note that there are many other E-Groups that I have not investigated, including ones that are concerned with only a single teacher, e.g. Nisargadatta, Vivekananda. Many now operate through yahoo and the complete list of those may be searched here. Descriptions and links to many groups can be found at Nonduality.com.