FYI - I sent a general description of the problem and a link to this thread to the standard IHG email help address. Here is the reply I received:

"Thank you for contacting IHG Guest Relations to report a problem you have experienced, with e-mail correspondence intended for Club members not coming to you. This is potentially a very significant issue, so we sincerely appreciate your report. More importantly, I offer my personal apology to you for this failure.

Your report has been forwarded to a technical team that handles online issues related to Club members. I would guess that they are probably aware of this issue already, but your comments could be very helpful because of the link to the Flyertalk forum. There may be significant descriptions and clues available there."