I think a more general answer is just to go ahead and use MIME. (Note: the mailx -m option mentioned earlier is not universal; for example, AIX doesn't have it).

Here's what I cobbled together out of parts of two (individually incorrect) answers on unix.com. Once you have the MIME skeleton in place, it's trivial to add body text,
more attachments, etc. Obviously, you change the encoding and use uuencode if you're sending a binary.

I hope none of the micro-changes I made to hide site identification, etc., break this thing, for indeed, it worketh :-)


#!/usr/bin/ksh
# Force environment for running under cron:
. $HOME/.profile
cd $HOME/script
rm -f cqsumm.csv 2>/dev/null
OUTFILE=$(date +%Y%m%d)cqsumm.csv
ADDRS=this@there.com,that@there.com,me@mydomain
sqlplus f_maint/f_maint @cqsumm
mv cqsumm.csv ${OUTFILE}
# It's a lot more convenient for the customer to open an attachment,
# so I replaced this next line with the sendmail/MIME code
# that comes after:
#cat ${OUTFILE} | mail -s"-secure- Coding queue summary" ${ADDRS}
# The -secure- in the Subject triggers email encryption through the Zix gateway. (very site-specific, that)
# This is required by HIPAA.
cat > foo << EOF
Subject: -secure- Coding queue summary
To: ${ADDRS}
MIME-Version: 1.0
Content-Type: Multipart/Mixed; boundary="MIME_BOUNDARY"
--MIME_BOUNDARY
Content-Type: text/plain; charset=us-ascii; NAME=${OUTFILE};
Content-transfer-encoding: 7bit
$(cat ${OUTFILE})
--MIME_BOUNDARY--
EOF
cat foo | /usr/sbin/sendmail -oi -t -f fnsw@myserver.mydomain ${ADDRS}