Find the file that corresponds to a certain message in Mail.app? Every message in Mail.app corresponds to a file in the filesystem (typically located somewhere here /Users/[username]/Library/Mail/V3/[account name]).

Is there an easy way to locate the corresponding file? Searching for contents (phrases) of the message does not seem to work. I want to add "Finder tags" to certain messages.
I'm tempted to say the easiest way to do a file contents search in what Finder would consider a System location would be EasyFind - freeware, though it's one app I'd happily pay for. [No affiliation]

You can drag a folder to define the search domain, then search by Phrase in File Contents. You can either QuickLook the result, or right click &amp; open in Mail or Reveal in Finder

I picked a fairly innocuous monthly summary from Backblaze as an example…



One thing to note is that the same mail may appear in more than one location. I really don't know why this is.