Make gnus-output-to-rmail appending work better

* lisp/gnus/gnus-util.el (gnus-output-to-rmail): Ensure we have a
blank line before the next line when using mbox format (bug#39580).

1 files changed, 6 insertions, 0 deletions

diff --git a/lisp/gnus/gnus-util.el b/lisp/gnus/gnus-util.el
index 807bd6a14af..ef811c65b86 100644
--- a/lisp/gnus/gnus-util.el
+++ b/lisp/gnus/gnus-util.el
@@ -1013,6 +1013,12 @@ FILENAME exists and is Babyl format."
                 (rmail-swap-buffers-maybe)
                 (rmail-maybe-set-message-counters))
               (widen)
+              (unless babyl
+                (goto-char (point-max))
+                ;; Ensure we have a blank line before the next message.
+                (unless (bolp)
+                  (insert "\n"))
+                (insert "\n"))
               (narrow-to-region (point-max) (point-max)))
             (insert-buffer-substring tmpbuf)
             (when msg