I have now implicitly told Gmail that these emails are not spam. I thought it was odd I hadn't had many (any!!) ehMac notification recently, and then realized that certain threads i had subscribed to had definitly had additonal posts which should have prompted notifications. Assured it wasn't Gmail en masse (I get a lot of email!), I checked spam and voilà!
Seems something related to the server switch (IP, host, ??) has popped with mass mail blacklists!?