I have used mu4e for email searching too. Based on the code in this post, I found it is quite easy to integrate mu4e with gnus too. The following code is for that, the mu4e version is 0.918, Emacs version is 25.3.
Same as code to integrate notmuch with gnus, there’s no general implementation of hy-notmuch-file-to-group, so you need to revise it for your own configuration.
(require 'mu4e) (require 'org-gnus) (defun hy-mu4e-maildir-to-group (maildir) "Calculate the Gnus group name from the given maildir. Example: IN: /outlook/Inbox OUT: nnmaildir+outlook:Inbox " (replace-regexp-in-string "^/\\([^/]+\\)/\\([^/]+\\)" "nnmaildir+\\1:\\2" maildir t)) (defun hy-mu4e-goto-message-in-gnus () "Open a summary buffer containing the current mu4e article." (interactive) (let ((group (hy-mu4e-maildir-to-group (mu4e-message-field-at-point :maildir))) (message-id (mu4e-message-field-at-point :message-id))) (if (and group message-id) (org-gnus-follow-link group message-id) (message "Couldn't get relevant infos for switching to Gnus.")))) (define-key mu4e-headers-mode-map (kbd "C-c C-c") 'hy-mu4e-goto-message-in-gnus) (define-key mu4e-view-mode-map (kbd "C-c C-c") 'hy-mu4e-goto-message-in-gnus)