We've been having a bit of trouble with our emails for the past few days, certain email providers are filtering out our emails before they reach members' inboxes (eg Hotmail). This is because a spam blacklist has added our server to their spam list. Nothing to do with the Org, it was email from another site on our server that has been flagged.

Our hosts are on the job but in the meantime I've switched us over to a third party email server. This should alleviate the immediate problem but may well have unintended consequences. Give us a shout if you stop receiving email subscriptions and other notifications.