diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 66c9f79006c..d8fdedfdbbd 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2012-02-14  Glenn Morris  <rgm@gnu.org>
+
+	* mail/smtpmail.el (smtpmail-query-smtp-server): Give it a doc.
+
 2012-02-14  Lars Ingebrigtsen  <larsi@gnus.org>
 
 	* mail/smtpmail.el (smtpmail-query-smtp-server): Fix typo in the
diff --git a/lisp/mail/smtpmail.el b/lisp/mail/smtpmail.el
index 8c56d926e0e..bbd8d7ce1ef 100644
--- a/lisp/mail/smtpmail.el
+++ b/lisp/mail/smtpmail.el
@@ -1,6 +1,6 @@
 ;;; smtpmail.el --- simple SMTP protocol (RFC 821) for sending mail
 
-;; Copyright (C) 1995-1996, 2001-2012  Free Software Foundation, Inc.
+;; Copyright (C) 1995-1996, 2001-2012 Free Software Foundation, Inc.
 
 ;; Author: Tomoji Kagatani <kagatani@rbc.ncl.omron.co.jp>
 ;; Maintainer: Simon Josefsson <simon@josefsson.org>
@@ -596,6 +596,12 @@ The list is in preference order.")
   (mapconcat 'identity (cdr response) "\n"))
 
 (defun smtpmail-query-smtp-server ()
+  "Query for an SMTP server and try to contact it.
+If the contact succeeds, customizes and saves `smtpmail-smtp-server'
+and `smtpmail-smtp-service'.  This tries standard SMTP ports, and if
+none works asks you to supply one.  If you know that you need to use
+a non-standard port, you can set `smtpmail-smtp-service' in advance.
+Returns an error if the server cannot be contacted."
   (let ((server (read-string "Outgoing SMTP mail server: "))
 	(ports '(25 587))
 	stream port prompted)
@@ -608,8 +614,7 @@ The list is in preference order.")
 				(open-network-stream "smtp" nil server port)
 			      (quit nil)
 			      (error nil))))
-	  ;; We've used up the list of default ports, so query the
-	  ;; user.
+	  ;; We've used up the list of default ports, so query the user.
 	  (when (and (not ports)
 		     (not prompted))
 	    (push (read-number (format "Port number to use when contacting %s? "