-Currently SASL security layers are not supported for SMTP. The SASL
-SMTP code in nmh will always negotiate an unencrypted connection.
+Currently SASL security layers are not supported for SMTP. nmh's SMTP SASL code
+will always negotiate an unencrypted connection. This means that while the SMTP
+authentication can be encrypted, the subsequent data stream can not. This is in
+contrast to nmh's POP3 SASL support, where encryption is supported for both the
+authentication and the data stream.