Hello today I noticed that many of my typical notification messages were missing/delayed (registration notifications, new ad notifications, ad expiration emails, etc.). Basically all system messages. I usually get several dozen everyday, so it was pretty easy to notice there was some sort of issue.
So I started testing and sure enough all messaging systems on my site seem to not be working (or more likely seriously delayed) as I am starting to see some system messages coming in 30 minutes to several hours delayed.
Any idea how to start troubleshooting this? Hosting issue, theme issue, wordpress issue?