How to send email from Terminal?

How to send email from Terminal?

bash email terminal

bash

here-document gives 'unexpected end of file' error

bash email heredoc

bash

Sending HTML mail using a shell script

html linux email bash sendmail

bash

Sending mail from a Bash shell script

macos bash email shell

bash

How to insert a delay between pipelining commands in a bash script. E.g. cat file | telnet mail.domain.com 25

linux bash email telnet

bash

Is there an implementable (non-theoretical) way to prove if email address belong to real email account?

java php bash email

bash

Bash, obtain email body from a text file including the email

bash email unix

bash