Then follow the steps I described and see if that helps. I am unsure of what email you use or I'd try to help with that, but following what I said as well as making sure all SH emails are in your contact list as I told Daisy, should help. If it doesn't then it's not on your end. I currently am not having any issues with notifications that I know of, so it may be with just certain people, which doesn't make much sense unless it's because of email carrier (services like yahoo, aol, and msn on average take a lot longer to receive automated emails or subscription emails than Gmail and some other providers). Either way, these are just good steps to take and if it still doesn't help then at least you troubleshooted it and did all within your power and know that SH may need to put attention to it.