Send and receive mail. More information: https://manned.org/mailx.
Ctrl+D
):mailx -s "subject" to_addr
echo "content" | mailx -s "subject" to_addr
mailx -s "subject" to_addr < content.txt
mailx -s "subject" -c cc_addr to_addr
mailx -s "subject" -r from_addr to_addr
mailx -a path/to/file -s "subject" to_addr