Say I've committed r123, r124 and r125 and someone else commits r130 as a followup to all three of those (e.g. with a commit summary like "Revert r123 and its followups r124, r125"), then I'll get three notification e-mails, one for each of my commits being followed up on.
This happened just now with https://static-codereview.wikimedia.org/MediaWiki/78837.html, which was marked as a followup to both https://static-codereview.wikimedia.org/MediaWiki/78824.html and https://static-codereview.wikimedia.org/MediaWiki/78786.html (because they all mention T16869) and I got two followup notifications.
Version: unspecified
Severity: enhancement