+--with-cyrus-sasl (DEFAULT is without)
+ Enable SASL support for SMTP and POP via the Cyrus SASL library.
+ This is used for the POP AUTH and SMTP AUTH protocols. This supports
+ a wide variety of security mechanisms, including Kerberos/GSSAPI.
+ Session encryption via SASL is supported for both POP and SMTP
+ (depending on server-side support and the security mechanism in use).
+
+--with-tls (DEFAULT is without)
+ Enable TLS session encryption support for SMTP via the STARTTLS command.
+
+--with-readline (DEFAULT is to autodetect)
+ Enable support for readline functionality (command history/editing) at
+ the WhatNow? prompt.
+