Untitled

echo "body" | mail -s "subject" my@email.com

uuencode /path/to/file file_name.ext | mail -s subject my@email.com

v_mailpart="$(uuidgen)/$(hostname)"
echo "To: my@email.com
Subject: subject
Content-Type: multipart/mixed; boundary="$v_mailpart"
MIME-Version: 1.0

This is a multi-part message in MIME format.
--$v_mailpart
Content-Type: text/html
Content-Disposition: inline

<html><body>Message text itself.</body></html>

--$v_mailpart
Content-Transfer-Encoding: base64
Content-Type: application/octet-stream; name=file_name.ext
Content-Disposition: attachment; filename=file_name.ext

`base64 /path/to/file`
 --$v_mailpart--" | /usr/sbin/sendmail -t

echo "body" | mutt -s "subject" -a attachment0 attachment1 [...] -- my@email.com