+--with-mts=MTS (DEFAULT is smtp)
+ Specify the default mail transport system you want to use. The three
+ acceptable options are "smtp" (which is the default),
+ "sendmail/smtp", and "sendmail/pipe". This value will be put into
+ the mts.conf file. You may find it convenient to specify a value
+ at configure-time, however, so that each time nmh is reinstalled,
+ the right value will be there.
+
+ If you use "smtp", this will enable a direct SMTP (simple mail
+ transport protocol) interface in nmh. When sending mail, instead
+ of passing the message to the mail transport agent, `post' will
+ open a socket connection to the mail port on the machine specified
+ in the `mts.conf' file (default is localhost), and speak SMTP
+ directly.
+
+ If you use "sendmail/smtp", then `post' will send messages by forking a
+ local copy of sendmail. Currently it will still speak SMTP with
+ this local copy of sendmail.
+
+ If you use "sendmail/pipe", then `post' will open a pipe to the
+ sendmail program and invoke it with the '-t' and '-i' options
+ and write the message to sendmail's standard input. Note that
+ some nmh functionality is not available in this mode.
+
+--with-ndbm=LIB (DEFAULT is to autodetect)
+--with-ndbmheader=HEADER (DEFAULT is to autodetect)
+ Specify the header file (eg ndbm.h) and library (eg ndbm) to use
+ to compile against the ndbm database library. By default, configure
+ will try various possibilities until it finds one that works; this
+ option only needs to be specified if the autodetection fails or
+ makes the wrong choice.
+
+ If either of these options is given then the other must also be
+ specified.
+
+--with-smtpserver='SMTPSERVER' (DEFAULT is localhost)
+ If this option is not specified, the mts.conf file will contain
+ the line "servers: localhost", which may be manually edited later.
+ You may find it convenient to specify a value at configure-time,
+ however, so that each time nmh is reinstalled, the right value will be
+ there.
+
+ See the mh-tailor(5) man page for full documentation of "servers:".
+
+--with-cyrus-sasl (DEFAULT is to autodetect))
+ 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 to autodetect)
+ Enable TLS session encryption support for SMTP via the STARTTLS command
+ and TLS at connection start for both SMTP and POP.
+
+--with-oauth (DEFAULT is to enable if curl is installed)
+ Enable OAuth2 authentication for SMTP and POP.
+
+--with-readline (DEFAULT is to autodetect)
+ Enable support for readline functionality (command history/editing) at
+ the WhatNow? prompt.