Gnus: Applying splits to old messages

Question

I am migrating my email workflow to gnus. I want to use splitting to keep things organized and for the splits to take effect on the server. I think my splits are working for incoming mail, but I want to sort my old mail too.

(setq gnus-select-method '(nnimap "outlook.office365.com"
                  (nnir-search-engine imap)
                  (nnimap-stream starttls)
                  (nnimap-split-download-body t)
                  (nnimap-split-predicate "UNDELETED")
                  (nnimap-split-fancy  (| ("MailScanner4-SpamCheck" "spam" "spam\.detected")
                               (from ".*@spammer.com" "mail\.custom\.spams")
                               (from ".*acm.org" "mail.acm")
                               "mail\.misc"))))

Answer 1

3 steps:

1. Select your mails:

    M P b
   

2. Respool them:

    B r RET RET
   

3. Be happy