+.PP
+If
+.B nmh
+has been compiled with OAuth support, the
+.B \-sasl
+and
+.B \-saslmech xoauth2
+switches will enable OAuth authentication. The
+.B \-user
+switch must be used, and the
+.I user-name
+must be an email address the user has for the service, which must
+be specified with the
+.B \-authservice
+.I service
+switch. Before using this, the user must authorize nmh by running
+.B mhlogin
+and grant authorization to that account. See the
+.B mhlogin
+man page for more details.
+.PP
+If
+.B nmh
+has been compiled with TLS support, the
+.B \-initialtls
+switch will require the negotiation of TLS when connecting
+to the remote POP server. The
+.B \-initialtls
+switch will negotiate TLS immediately after the connection has taken place,
+before any POP commands are sent or received. Data encrypted by TLS is
+labeled `(tls-encrypted)' and `(tls-decrypted)` with viewing the POP
+transaction with the
+.B \-snoop
+switch. The
+.B \-notls
+switch will disable all attempts to negotiate TLS.
+.PP
+When using TLS the default is to verify the remote certificate and SubjectName
+against the local trusted certificate store. This can be controlled by
+the
+.B \-certverify
+and
+.B \-nocertverify
+switches. See your OpenSSL documentation for more information on certificate
+verification.