Cleanup email header streams after use

Also uses less streams to begin with.

mailfilter-parse.lisp

       (loop-file-until s (lambda (x) (declare (ignore x)))  #'parse-line hash))
     hash))
 
-(defun make-message-regex-test (regex)
-  (lambda (string)
-    (cl-ppcre:scan regex string)))
-
-(defun message-match (message pattern)
-  (let* ((test-func (make-message-regex-test (gethash "regex" pattern)))
-         (sb-impl::*default-external-format* :latin-1)
-         (stream (mel:message-header-stream message))
-         (test))
-    (loop for line = (read-line stream nil 'eof) do
-      (or (eq line 'eof) (setf test (funcall test-func line)))
-          until (or (eq line 'eof) test))
+(defun message-match (stream pattern)
+  (let ((regex (gethash "regex" pattern))
+        (test))
+    (labels ((test-func (string) (cl-ppcre:scan regex string)))
+      (loop for line = (read-line stream nil 'eof) do
+        (or (eq line 'eof) (setf test (test-func line)))
+            until (or (eq line 'eof) test)))
     test))
 
-(defun make-message-match (message)
-  (lambda (pattern)
-    (message-match message pattern)))
-
 (defun handle-message (message patterns)
-  (labels ((my-message-match (pattern) (message-match message pattern)))
-    (find-if #'my-message-match patterns)))
+  (let* ((sb-impl::*default-external-format* :latin-1)
+        (stream (mel:message-header-stream message)))
+    (labels ((my-message-match (pattern) (message-match stream pattern)))
+      (find-if #'my-message-match patterns)
+      (close stream))))
 
 (defun filter-maildir-folder (mailfilter)
   (let* ((mailfilter-rules (read-mailfilter-file mailfilter))