Document 'smtp-auth' in auth-source info

* doc/misc/auth.texi (Help for users): Mention 'smtp-auth' key,
add cross-reference to smtpmail.info.
* doc/misc/smtpmail.texi (Authentication): Fix markup.

2 files changed, 9 insertions, 3 deletions

diff --git a/doc/misc/auth.texi b/doc/misc/auth.texi
index 61dc62e7711..f8fcb642901 100644
--- a/doc/misc/auth.texi
+++ b/doc/misc/auth.texi
@@ -227,6 +227,11 @@ machine YOURMACHINE login YOU password SMTPPASSWORD port 433
 machine YOURMACHINE login YOU password GENERALPASSWORD
 @end example
 
+If you wish to specify a particular SMTP authentication method to use
+with a machine, you can use the @code{smtp-auth} keyword.
+@xref{Authentication,, Authentication, smtpmail, Emacs SMTP Library},
+for available methods.
+
 For url-auth authentication (HTTP/HTTPS), you need to put this in your
 netrc file:
 
diff --git a/doc/misc/smtpmail.texi b/doc/misc/smtpmail.texi
index e19d0f689d3..f4367b35377 100644
--- a/doc/misc/smtpmail.texi
+++ b/doc/misc/smtpmail.texi
@@ -269,9 +269,10 @@ is known as ``Simple Authentication and Security Layer'' (SASL).
 There are various SASL mechanisms, and this library supports three of
 them: CRAM-MD5, PLAIN, and LOGIN, where the first uses a form of
 encryption to obscure your password, while the other two do not.  It
-tries each of them, in that order, until one succeeds.  You can assign
-a specific authentication mechanism to a server by including a key
-smtp-auth with a value of the preferred mechanism.
+tries each of them, in that order, until one succeeds.  You can
+override this by assigning a specific authentication mechanism to a
+server by including a key @code{smtp-auth} with the value of your
+preferred mechanism in the appropriate @file{~/.authinfo} entry.
 
 @node Encryption
 @chapter Encryption