Fix test_mailbox by supporting context manager protocol for get_file() returns.
diff --git a/Misc/NEWS b/Misc/NEWS
index afbf04c..827640a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -57,6 +57,9 @@
 Library
 -------
 
+- Support context manager protocol for file-like objects returned by
+  mailbox ``get_file()`` methods.
+
 - Issue #10246: uu.encode didn't close file objects explicitly when filenames
   were given to it.  Patch by Brian Brazil.