In my Phabricator instance I have a personal Herald rule to add me as auditor on new commits. That works like a charm. However after recent Phabricator update I started to get an e-mail about every commit where I've been added as auditor.
My guess is that, the E-mail preferences section was created or was changed to give you more control and now I'm getting e-mails for actions I haven't received them before.
{F220363}
Since my own Herald rule added myself as auditor, then this should be considered as my own activity and I shouldn't get any e-mail notifications about it.