When a bot edits a page on your watchlist, and your preferences are configured to send you an email notification on new edits to watchlisted pages (and assuming the wiki is configured to do so), it usually doesn't result in an edit notification (every once in a while it does, but I haven't been able to find any sort of common element to these cases, so I don't know what causes it). This wouldn't be a problem, except that if an edit notification isn't emailed for that edit, it also never gets sent for any subsequent edit to that page, meaning that if you don't use your watchlist to keep up with edits to a wiki, you can miss subsequent changes to that page for an indefinite period of time.
I've observed this across several wikis on Wikia as well as on the Minecraft Wiki (http://minecraftwiki.net), and across multiple versions of MediaWiki.
- T15992: Add user preference to opt out of email notification for bot edits (similar to $wgEnotifMinorEdits)
- T29884: enotif doesn't send email if page on watchlist edited following a minor edit and enotif not configured to send minor edits.
- T31055: $wgEnotifUserTalk forced showing option 'minor edits notification' in Preferences
- T51749: On minor edit, no email notification for talk page (enotifusertalkpages)
- T49910: Echo: do not send talkpage notifications if the edit is both made by a bot-flagged account, and marked as minor
- T142727: Set $wgEnotifMinorEdits true throughout WMF, and instead use $wgDefaultUserOptions['enotifminoredits']