We have had a Email functionality included in DE8 since DE8.0 but it had one big limitation and that was that it couldn't use SMTP with TLS which in reality is most modern SMTP services. 

Services like GMAIL etc will demand that you use TLS and so will most public SMTP services. We are therefore happy to include SenEmail (command line tool) in our distribution to improve the direct emailing functionality in DE8.

Common:

-t ADDRESS [ADDR ...] to email address(es)

-u SUBJECT message subject

-m MESSAGE message body

-s SERVER[:PORT] smtp mail relay, default is localhost:25

Optional:

-a FILE [FILE ...] file attachment(s)

-cc ADDRESS [ADDR ...] cc email address(es)

-bcc ADDRESS [ADDR ...] bcc email address(es)

-xu USERNAME username for SMTP authentication

-xp PASSWORD password for SMTP authentication

Paranormal:

-b BINDADDR[:PORT] local host bind address

-l LOGFILE log to the specified file

-v verbosity, use multiple times for greater effect

-q be quiet (i.e. no STDOUT output)

-o NAME=VALUE advanced options, for details try: --help misc

-o message-content-type=<auto|text|html>

-o message-file=FILE -o message-format=raw

-o message-header=HEADER -o message-charset=CHARSET

-o reply-to=ADDRESS -o timeout=SECONDS

-o username=USERNAME -o password=PASSWORD

-o tls=<auto|yes|no> -o fqdn=FQDN

Help:

--help the helpful overview you're reading now

--help addressing explain addressing and related options

--help message explain message body input and related options

--help networking explain -s, -b, etc

--help output explain logging and other output options

--help misc explain -o options, TLS, SMTP auth, and more