I should have done what the manual says: 6.4.6 Fancy Mail Splitting
For years, at least since 2008, but likely far longer, I’ve been splitting my mail building on someone else’s code that I got on the Internet. It worked, but it had a few quirks that I had not really noticed.
There’s a big difference between
placed at the end of
(setq nnimap-split-fancy '(| ("subject" "media alert" "INBOX.pressreleases") [...] snipped many lines (: (lambda () (car (bbdb/gnus-split-method)))) ;; Default mailbox "INBOX"))
Determined Adam Sjøgren encouraged me to edebug my nnimap-split-fancy code (see nnmail-mail-splitting-decodes). The manual is always right. In my defence, I’d like to say, “You can’t understand the manual, until you do.”
The code I took from a stranger comes with “”, and adds an extra pair of ().
Having both, doing gnus-summary-respool-trace (B t) on unsplitable messages will return:
(: (lambda nil (car (bbdb/gnus-split-method)))) message will go to mail.misc
Removing the “” while keeping the equally superfluous (), B t will return:
(: (lambda nil (car (bbdb/gnus-split-method)))) message will go to bogus
When removing both, following the example in the manual, B t will return:
(: (lambda nil (car (bbdb/gnus-split-method)))) message will go to INBOX
Which is cleaner: my IMAP folder collection includes neither mail.misc nor bogus, but an INBOX it has.