Did the security update kill my email?
Both my iMac and MacBook Pro running Yosemite 10.10.2 aren’t receiving all my emails, although my iPad and Windows PC are. When I open Mail it can be hours before emails arrive, then all in one slug. I get the triangle with exclamation mark appearing, suggesting I’m disconnected from the internet, and the unread emails number showing although I’ve read every email on the screen. Now, two days after this started, the MacBook Pro is not receiving any emails at all. This all started after I received Security Update 2015-002 Version 1.0. Jeremy Taylor I don’t have enough data points yet to be sure whether this was caused by the security update, but I agree it’s a Yosemite bug. Apple does too, because it posted a support page in entitled “Mail (Yosemite): If you can’t receive messages”. It’s a list of the obvious first things to try, like checking passwords and making sure you aren’t in the middle of downloading a huge attachment. This is what Apple does when it has a rare bug developers can’t reproduce. The page is designed to filter out things that could cause the same symptoms, in the hope people who submit a bug at apple.com/ feedback/mail.html, can provide hard data.
Sending feedback to Apple whenever you encounter a bug will help vote that particular problem to the top of the queue for fixing.