Sort authentication methods alphabetical and mark CRAM-MD5 and DIGEST…

…-MD5 as DEPRECATED

README.rst

@@ -70,25 +70,25 @@ methods, in order of preference:
 
 .. _RFC-2554: https://www.ietf.org/rfc/rfc2554.txt
 
-GSSAPI
-------
+CRAM-MD5 (DEPRECATED)
+--------
 
-The GSSAPI authentication method uses Kerberos 5 protocol (RFC-4120_).
-Does not use user/password.
-Requires Service Principal ``gssapi_principal`` parameter and
-has an optional Credentials Cache ``gssapi_cname`` parameter.
-Requires DNS and Key Distribution Center (KDC) setup.
-It is considered the most secure method of SMTP authentication.
+**DEPRECATED**
+This authentication method is no longer secure.
 
-**Note:** The GSSAPI authentication method is only supported
-if the krb5_ php extension is available.
+The CRAM-MD5 authentication method has been superseded by the DIGEST-MD5_
+method in terms of security.  It is provided here for compatibility with
+older SMTP servers that may not support the newer DIGEST-MD5 algorithm.
 
-.. _RFC-4120: https://tools.ietf.org/html/rfc4120
-.. _krb5: https://pecl.php.net/package/krb5
+**Note:** The CRAM-MD5 authentication method is only supported if the
+AUTH_SASL_ package is available.
 
-DIGEST-MD5
+DIGEST-MD5 (DEPRECATED)
 ----------
 
+**DEPRECATED**
+This authentication method is no longer secure.
+
 The DIGEST-MD5 authentication method uses `RSA Data Security Inc.`_'s MD5
 Message Digest algorithm.  It is considered a more secure method of SMTP
 authentication than PLAIN or LOGIN, while still vulnerable to MitM attacks
@@ -99,28 +99,21 @@ AUTH_SASL_ package is available.
 
 .. _RSA Data Security Inc.: https://www.rsasecurity.com/
 
-CRAM-MD5
---------
-
-The CRAM-MD5 authentication method has been superseded by the DIGEST-MD5_
-method in terms of security.  It is provided here for compatibility with
-older SMTP servers that may not support the newer DIGEST-MD5 algorithm.
-
-**Note:** The CRAM-MD5 authentication method is only supported if the
-AUTH_SASL_ package is available.
-
-SCRAM-SHA
---------
+GSSAPI
+------
 
-In cryptography, the Salted Challenge Response Authentication Mechanism (SCRAM)
-is a family of modern, password-based challenge–response authentication mechanisms
-providing authentication to a server.
+The GSSAPI authentication method uses Kerberos 5 protocol (RFC-4120_).
+Does not use user/password.
+Requires Service Principal ``gssapi_principal`` parameter and
+has an optional Credentials Cache ``gssapi_cname`` parameter.
+Requires DNS and Key Distribution Center (KDC) setup.
+It is considered the most secure method of SMTP authentication.
 
-Available mechanisms are SCRAM-SHA-1, SCRAM-SHA-224, SCRAM-SHA-256, SCRAM-SHA-384
-and SCRAM-SHA-512.
+**Note:** The GSSAPI authentication method is only supported
+if the krb5_ php extension is available.
 
-**Note:** The SCRAM-SHA authentication method is only supported if the
-AUTH_SASL_ package is available.
+.. _RFC-4120: https://tools.ietf.org/html/rfc4120
+.. _krb5: https://pecl.php.net/package/krb5
 
 LOGIN
 -----
@@ -138,6 +131,19 @@ PLAIN
 The PLAIN authentication method sends the user's password in plain text.
 This method of authentication is not secure and should be avoided.
 
+SCRAM
+--------
+
+In cryptography, the Salted Challenge Response Authentication Mechanism (SCRAM)
+is a family of modern, password-based challenge–response authentication mechanisms
+providing authentication to a server.
+
+Available mechanisms are SCRAM-SHA-1, SCRAM-SHA-224, SCRAM-SHA-256, SCRAM-SHA-384
+and SCRAM-SHA-512.
+
+**Note:** The SCRAM-SHA authentication method is only supported if the
+AUTH_SASL_ package is available.
+
 XOAUTH2
 -------