Sorry, a 2-year-old pressed send before I had finished this message. :-)
If you have a Yahoo! affiliated email address (and Yahoo!-related domains), you may have heard that Yahoo! has recently broken pretty much all email list access by instituting an over-cautious email policy called DMARC. We may be forced to unsubscribe all Yahoo! email address users on MASON-INTEREST and ECJ-INTEREST.
My suggestion to all Yahoo! email users who wish to continue to participate in email lists is to switch to another provide, such as Hotmail or Gmail.
Here's some more information: