bash-4.1$ cat test.txt
HelloWorld !

bash-4.1$ uuencode test.txt test_attachment.txt|mailx -s 'testing' mail@mail.com

begin 664 test_attachment.txt
/2&5L;&]7;W)L9"`A(`H*
`
end

From: Alice <alice@example.edu>
To: Bob <bob@example.com>
Subject: Those files you requested

Here you go:

begin 644 something.tar.Z
M'YV04HH$(=*D"("#"!,J7,BPH<.'$"-*1`BC(@P;%0%8C'$#H:*'#U:'%EQ
M1@T`,63<F!&CQHP;,&3,T!@#QLJ9(&!,W,FSI^?`.K,H1-&#@@0`-*02?.&
M#E"&2IDZ?4JUJM6K6+-JE9CE31T08<;0J1.&#9L(,K@H2,G+)TR9$#009-F
MS@%6_/JW<NWK]^_@`,+'DRXL.'#B!,K7LRXL>/'D"-+GDRYLN7+F#-KWLRY
ML^?/H$.+'DVZM.G3J%.K7LVZM>O7L&/+GDV[MNW;N'/KWLV[M^_?P(,+'TZ
JN/'CR),K7ZN?/GT*-+GTZ]NO7KV+-KWZ]N_?OX,.+'T^^O/GSZ',#
`
end

--
Alice

$ uuencode test.txt test_attachment.txt >file.uue
$ mailx -A file.uue -s "testing" someone@example.com </dev/null

uuencode test.txt test_attachment.txt | mailx **-m** -s 'testing' mail@mail.com

echo "
Subject: My Email Subject at `date "+%m/%d/%Y %r UTC"`
MIME-Version: 1.0
Content-type: multipart/mixed; boundary="^A^A^A^A^A"
Content-Transfer-Encoding: 7bit

--^A^A^A^A^A
Content-Type: text/plain; charset=US-ASCII; name="BDY.TXT"
Content-Disposition: inline; filename="BDY.TXT"
Content-Transfer-Encoding: 7bit

My Email Subject at `date "+%m/%d/%Y %r UTC"`

--^A^A^A^A^A
Content-Type: text/plain; charset=US-ASCII; name="ZIP_FILE"
Content-Disposition: attachment; filename="ZIP_FILE"
Content-Transfer-Encoding: 7bit

" > /tmp/ZIP_FILE

cat /tmp/MySourceZipFile >> /tmp/ZIP_FILE
echo "
--^A^A^A^A^A--" >> /tmp/ZIP_FILE


/usr/sbin/sendmail "GodSend@Heaven.godcom" < /tmp/ZIP_FILE