mailing list problems fixed

[Ken Olum <kdo cosmos phy tufts edu>]

On Wednesday I installed a new version of the exim mailer without
checking it out carefully enough.  The result was to break all mailing
lists on cosmos.phy.tufts.edu.  Thanks for Laura for calling this to my
attention yesterday.  If you sent a message to the list and got back an
error on the order of "unknown user boston-change-ringers", you should
send your message again now.

Sorry for the trouble.

                                        Ken