I see there are multiple threads started about this issue. Yes, I have been having the same issues with watch lists and owner logs. For most people I truly believe it is not an ISP or e-mail delivery issue. Up until a few weeks ago everything was fine - got all the e-mails from GC/Groundspeak. Now I only get about 30-40% of the e-mails that should have been sent.
I host my own e-mail server and spam filtering. There are no logs about failed attempts to deliver. According to my end, the e-mail never existed.
I'd be happy to help troubleshoot this issue if needed.
Thanks!