[[http://msmtp.sourceforge.net/]]

[[https://wiki.archlinux.org/index.php/Msmtp]]

Kept getting an error:
<code>
# cd /usr/local/src/msmtp-1.4.27]
# make check
Making check in src
make[1]: Entering directory `/usr/local/src/msmtp-1.4.27/src'
  CCLD   msmtp
tls.o: In function `tls_init':
/usr/local/src/msmtp-1.4.27/src/tls.c:1100: undefined reference to `gnutls_priority_set_direct'
collect2: ld returned 1 exit status
make[1]: *** [msmtp] Error 1
make[1]: Leaving directory `/usr/local/src/msmtp-1.4.27/src'
make: *** [check-recursive] Error 1
</code>

The solution is simple:
<code>
# ./configure --with-ssl=openssl
# ./make check
# ./make install
</code>

Hint page:  [[http://www.andreaswacker.com/blog/2012/02/04/centos-source-install-wget-113-and-gnutls/]]