$ ./sparkpostSMIME.py -h
usage: sparkpostSMIME.py [-h] [--encrypt] [--sign] [--send_api] emlfile

Send an email file via SparkPost with optional S/MIME encryption and signing.

positional arguments:
  emlfile     filename to read (in RFC822 format)

optional arguments:
  -h, --help  show this help message and exit
  --encrypt   Encrypt with a recipient certificate containing public key.
              Requires file.crt where file matches To: address.
  --sign      Sign with a sender key. Requires file.crt containing public key,
              and file.pem containing private key, where file matches From:
              address.
  --send_api  Send via SparkPost API, using env var SPARKPOST_API_KEY and
              optional SPARKPOST_HOST.

$ ./sparkpostSMIME.py testcases/img_and_attachment.eml --sign --encrypt
To: Bob <bob.lumreeker@gmail.com>
From: Steve <steve@thetucks.com>
Subject: Testing attachments etc
Content-Language: en-GB
MIME-Version: 1.0
Content-Type: application/pkcs7-mime; smime-type=enveloped-data; name=smime.p7m
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7m

MIMPPccGCSqGSIb3DQEHA6CDDz23MIMPPbICAQAxggHHMIIBwwIBADCBrDCBlzEL
MAkGA1UEBhMCR0IxGzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UE
:
:

$ export SPARKPOST_API_KEY=<<Your API key here>>
$ ./sparkpostSMIME.py testcases/img_and_attachment.eml --sign --encrypt --send_api

Opened connection to https://api.sparkpost.com/api/v1
Sending testcases/img_and_attachment.eml	From: Steve <steve@thetucks.com>	To: Bob <bob.lumreeker@gmail.com>
OK - in 1.152 seconds

usage: mimeshow.py [-h] [file]

Display internal header and MIME structure of a mail file in RFC822 format,
indented for ease of reading

positional arguments:
  file        filename to read. If file is absent, reads from the standard
              input (acts as a filter).

optional arguments:
  -h, --help  show this help message and exit

$ ./mimeshow.py testcases/img_and_attachment.eml 
To Bob <bob.lumreeker@gmail.com>
From Steve <steve@thetucks.com>
Subject Testing attachments etc
MIME-Version 1.0
Content-Type multipart/mixed; boundary="------------7D48652042860D0098C65210"
Content-Language en-GB

  Content-Type multipart/alternative; boundary="------------58C0BF87598336550D70EB95"

    Content-Type text/plain; charset=utf-8; format=flowed
    Content-Transfer-Encoding 7bit

    Content-Transfer-Encoding quoted-printable
    Content-Type text/html; charset="utf-8"

  Content-Type application/pdf; name="sparkpost-datasheet-tam-technical-account-management.pdf"
  Content-Transfer-Encoding base64
  Content-Disposition attachment; filename="sparkpost-datasheet-tam-technical-account-management.pdf"
 

$ ./sparkpostSMIME.py tests/declaration.eml --sign --encrypt | ./mimeshow.py 
To Bob <bob.lumreeker@gmail.com>
From Steve <steve@thetucks.com>
Subject Here is our declaration
Content-Language en-GB
MIME-Version 1.0
Content-Type application/pkcs7-mime; smime-type=enveloped-data; name=smime.p7m
Content-Transfer-Encoding base64
Content-Disposition attachment; filename=smime.p7m

# First, get the Python interpreter and git cli tool. Doesn't have to be version 3.6 specifically,
# that's just what Amazon Linux requires.
sudo yum install -y python36 git

# Create environment. Note your pip command names and options may vary depending on OS.
# The following is for Amazon Linux.
# Your OS may name this tool pip3 rather than using a version-specific name.
/usr/bin/pip-3.6 install --user pipenv

# Install project
git clone https://github.com/tuck1s/sparkySecure.git
cd sparkySecure

# Install dependencies into virtualenv, including some specific lib versions.
# Virtual environments take away tool version / paths pain, once you have one.
pipenv --python 3.6 install
pipenv shell

# Now inside our virtual env
export SPARKPOST_API_KEY=<<<YOUR API KEY HERE>>>

# If the following gives you help text, then you're good.
./sparkpostSMIME.py -h