HTML e-mails to this list are silently dropped?

list John P Martin
Mon, 18 Oct 2010 08:13:56 +0100
Message-Id: <user-49d9b1ec9904@xymon.invalid>

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                                                                              Your       [xymon] HTML e-mails to this list are silently dropped?         document:                                                                                                                                             was        user-18313e92e552@xymon.invalid                                               received                                                                   by:                                                                                                                                                   at:        10/18/2010 08:13:56 AM GDT