echo "Subject: sendmail test" | sendmail -v my@email.com

To: mymail@gmail.com
Subject: sendmail test two
From: me@myserver.com

And here goes the e-mail body, test test test
and new line

250 2.1.5 <mymail@gmail.com>... Recipient ok
354 Enter mail, end with "." on a line by itself

myserver.com: Name server timeout
mymail@gmail.com... Deferred: Name server: [127.0.0.1]: host
name lookup failure
Closing connection to [127.0.0.1]