# Pastebin 7sTEFYuU
#!/bin/sh

announce="$1"

if [ ! -r $announce ]; then
  echo "usage: $0 <foo.announce>"
  exit 1
fi

grep -F "Subject:
Cc:
To:" $announce > ${announce}.sign

echo "" >> ${announce}.sign

grep -vF "Subject:
Cc:
To:" $announce | gpg --clearsign >> ${announce}.sign

cat ${announce}.sign | msmtp -t
rm ${announce}.sign