+Support for CompuServe's RPA authentication method (rather similar to
+APOP) is available but also not included in the standard build. You
+can compile it in with 'configure --enable-RPA'.
+
+Support for Microsoft's NTLM authentication method is also available
+but not included in the standard build either. You can compile it in
+with 'configure --enable-NTLM'.
+
+Support for authentication using RFC1731 GSSAPI is available
+but also not included by default. You can compile it in with
+'configure --with-gssapi', which looks for GSSAPI support in standard
+locations (/usr, /usr/local). If you set --with-GSSAPI=DIR
+you can direct the build to look for GSSAPI support under DIR.
+
+Hooks for the OpenSSL library (see http://www.openssl.org/) are
+included in the distribution. To enable these, configure with
+--with-ssl; they are not included in the standard build. Fetchmail's
+configure script will probe some default locations for the
+include/openssl/ssl.h file. If this doesn't work (i. e. configure prints
+"SSL support enabled, but OpenSSL not found" and aborts), you need to
+give the explicit prefix of your OpenSSL installation (specify the
+directory that contains OpenSSL's "include" subdirectory), for instance:
+"--with-ssl=/example/path" would assume that you have an
+/example/path/include/openssl/ssl.h header file.
+
+2.2 Advanced options
+
+Specifying --with-kerberos=DIR or --with-kerberos5=DIR will tell the
+fetchmail build process to look in DIR for Kerberos support.
+Configure normally looks in /usr/kerberos and /usr/athena; if you
+specify this option with an argument it will look in DIR first.