some email doc improvments

--HG--
extra : convert_revision : svn%3Ab85faa78-f9eb-468e-a121-7cced6da292c%40705

scrapy/trunk/docs/ref/email.rst

@@ -1,4 +1,4 @@
-.. _topics-email:
+.. _ref-email:
 
 =============
 Sending email
@@ -29,15 +29,18 @@ MailSender class
 ================
 
 MailSender is the class used to send emails from Scrapy. It's
-currently only a warpper over the (IO blocking) smtplib
+currently only a wrapper over the (IO blocking) `smtplib`_
 library but it's gonna be ported to Twisted soon.
 
+.. _smtplib: http://docs.python.org/library/smtplib.html
+
 .. class:: scrapy.mail.MailSender(smtphost, mailfrom)
 
-    ``smtphost`` is a string with the SMTP host to use for sending the emails
+    ``smtphost`` is a string with the SMTP host to use for sending the emails.
+    If omitted, :setting:`MAIL_HOST` will be used.
 
     ``mailfrom`` is a string with the email address to use for sending messages
-    (in the ``From:`` header)
+    (in the ``From:`` header). If omitted, :setting:`MAIL_FROM` will be used.
 
 .. method:: send(to, subject, body, cc=None, attachs=None)
 

scrapy/trunk/docs/ref/settings.rst

@@ -441,9 +441,18 @@ MAIL_FROM
 
 Default: ``'scrapy@localhost'``
 
-Scope: ``scrapy.mail``
+Email to use as sender address for sending emails using the :ref:`Scrapy e-mail
+sending facility <ref-email>`.
 
-Host to use for sending notification emails from Scrapy.
+.. setting:: MAIL_HOST
+
+MAIL_HOST
+---------
+
+Default: ``'localhost'``
+
+Host to use for sending emails using the :ref:`Scrapy e-mail sending facility
+<ref-email>`.
 
 .. setting:: MEMDEBUG_ENABLED