I have no idea why you would have been dropped from the Yahoo list, but if you go to www.columbia-yachts.com
there is a link there for subscribing to both e-mail, or online forum. Same postings, just different delivery options.
As for Sailnet.com, if you click on the resources tab at the top here, there is still an e-mail list. For mail delivery you have to register, and select the mail option. It is a different format than the forum here, with different postings. While this particular forum is easy to use, it hasn't caught on yet.