Blaze, some tools to manipulate your emails

blaze aggregates many tools to manipulate emails. The goal is to iterate between high-level usages of emails and libraries such as mrmime, dkim or spf. It's an experimental repository!

A simple example of blaze

As we said, blaze has many tools which want to be used into an UNIX context. It permits to analyze, extract or stamp emails. This is an example of how to use blaze:

$ git clone https://github.com/dinosaure/blaze
$ cd blaze
$ opam pin add -y .
# Assume that ~/maildir/ is a Maildir directory which contains your emails
$ export MSG=$(blaze.mdir new -D ~/maildir/ | tail -n1)
# We have the Maildir of the last message
$ blaze.mdir get -D ~/maildir/ --new $MSG > new.eml
# We can verify DKIM signature
$ blaze.dkim verify new.eml
[OK]: blaze.org
# Or SPF results
$ blaze.spf analyze new.eml
[email protected] from 192.168.0.0: pass (expected: pass)
# And extract some informations from it
$ blaze.addr --without-name new.eml
[email protected]

How to craft & send an email?

blaze wants to be simple to send an email. First, you need to craft one with some meta-information. Then, you can attach a document to your email and then, pass it to blaze.send with your account credentials. You may be need another tool, conan, to be able to recognize the MIME type of the attachment.

$ blaze.make <<EOF \
  | blaze.make wrap --mixed
  | blaze.make put --type $(conan.file --mime image.png) \
    --encoding base64 image.png
  | blaze.send --sender foo@bar - smtp.bar
> Hello World!
> EOF

As you can see, you can craft and send your email along the UNIX pipe.

How to receive an email?

blaze provides a little server which is able to receive only one email. By default, it wants to listen on *:25. It's an implementation of a simple SMTP server and it waiting an email to save it then into your file-system:

$ sudo blaze.srv -o new.eml &
[1] PID
$ blaze.make <<EOF \
  | blaze.send --sender foo@bar -r admin@localhost
> Hello World!
> EOF
$ cat new.eml
Date: Thu, 6 Jan 2022 16:49:55 +0100
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=utf-8

Hello World!

Submit or send an email?

SMTP is a bi-diretional protocol where a SMTP server can be a client for another SMTP server. When you want to send an email, you have 2 possibilities:

1. send an email to a recipient directly under my identity concretized via my computer (my hostname, etc.)
2. send an email to a recipient through a certain identity provided by a SMTP server (like gmail.com)

For the first case, you want to use blaze.send which sends an email directly to the given SMTP server (on *:25) or the SMTP server of the first recipient. For instance, this command send an email to foo:25:

$ blaze.send --sender [email protected] -r bar@foo

However, you probably want some security mechanisms such as DKIM or SPF offered by a certain service like gmail.com. In that case, you want to submit an email to this service which will re-send your email under its authority with its security mechanisms:

$ blaze.submit --sender [email protected] --password ****** -r bar@foo

The second case ensure that the communication between you and the SMTP service is encrypted (via STARTTLS or over TLS). Otherwise, it does not try to send an email. Then, the submission server is not foo:25 like before but blaze.org:{465,587}. Usually, this service requires a password.

In both case, bar@foo will receive an email but:

• in the first case, it will receive the email as is
• in the second case, your serviteur (blaze.org) probably put some metadata to let bar@foo to verify the given email

blaze has received funding from the Next Generation Internet Initiative (NGI) within the framework of the DAPSI Project.