as per this page:
http://archives.postgresql.org/pgsql-general/
I sent an email to:
majordomo@postgresql.org
with this single line in it:
subscribe-digest pgsql-general
and got back this error email:
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subscribe-digest pgsql-general
**** The subscribe command did not succeed.
****
**** The command mode "digest" is invalid. The following command
**** modes, separated by hyphens ('-') or equals signs ('=') are valid:
**** noinform
**** nolog
**** nowelcome
**** quiet
**** rule
**** set
**** welcome
Valid commands processed: 1
0 succeeded, 0 stalled, and 1 failed.
-----------------------------------------