The word usually is crucial. So it might be that the code has some unknown effects also? I had not changed the plugins or themes when Actions were working. So I am stuck.
The choice of wording is NOT because there is some unknown issue with our code that is causing your issue. There are so many permutations of installs, types of themes, plugins, hosting environment etc that you can’t assume there will NO Problems with someones install.
That said….What you are experiencing …at least by descriptions may have more to do with corrupt DB files/tables than anything else. We have observed in the past – that larger data storage, prior to our 7.21/7.22 release were problematic and we suggested that users CLEAN-UP their DB prior to installing the update. What you describe as a CLEAN install is not the case unless it was done on a NEW WP Install w/o any prior instance of JM being installed.
If you did perform a CLEAN INSTALL with new WP Instance and new DB, than I can only assume you uploaded a back-up of your DB and or migrated data from a previous install ?
It appears that your DB (Instance) has/had been running for some time with the amount of applications you reported. I would highly suggest you READ the information supplied for the recent updates again.
If you migrated data to a new system than I can pretty much bet that you have corrupted DB tables and that may be causing the issue of the email stoppage, unless some other server configuration or plugin update is conflicting…which you say it’s not.
Either way, you should look at optimizing your DB to see if that helps clear up the issue.
Hope this helps.