OmniMix • Tutorial • Remailing • Individual Message Parameters

With the examples above OmniMix decides based on its settings how all of your messages heve to be treated. To influence the routing on an individual message-by-message basis you have to transmit corresponding instructions through certain message header values.

Ctrl_All_Header_Anon

The 'Always use Mixmaster for News / Mail' switches allow you to construct an opt-in or opt-out system, where the anonymization precondition can be overruled by an 'Anon Switch' header like 'O-Anon-Send: No'. But the decision about anonymization isn't the only way to achieve an individual treatment of your messages. You find all supported parameters and their (changeable) header representatives at the 'Header' tab:

Anon Switch	Set this header in your message to override the routing presets. '<switch>: no' sends the message directly, '<switch>: yes' means routing through the default remailer network, '<switch>: mixmaster' means routing through the Mixmaster network, '<switch>: yamn' means routing through the Yamn network. Different remailer networks means different remailer names, which is why with a remailer definition also an appropriate remailer chain definition compatible with the network you selected should be sent. Example: 'O-Anon-Send: Yes'
From Switch	Set this header in your message to override the 'From:' definition preset. '<switch>: ori' or '<switch>: no' leaves the 'From:' header of the original message untouched, '<switch>: mod' or '<switch>: yes' replaces the 'From:' address with the 'Anon' value, '<switch>: non' removes the 'From:' header without replacement. With 'ori', 'mod' and 'non' only the first 3 characters are significant, so that e.g. 'Original', 'Modify' and 'None' are valid parameters as well. Example: 'O-Anon-From: None'
Remail Chain	Set this header in your message to override the remailer chain preset. This allows you to choose the remailer chain on a per message basis. Example: 'O-Remailer-Chain: banana * * * * frell'
Msg Copies	Set this header in your message to override the message copies preset. This allows you to choose the number of copies sent to the remailer system on a per message basis. Values in a range from 1 to 10 are accepted. Example: 'O-Remailer-Copies: 6'
Remail Transp	Set this header in your message to override the remailer transparency encoding preset. As Mixmaster remailer systems interpret message data in a variety of ways with some of them ensuring message transparency according to RFC 821 section 4.5.2 (SMTP) and RFC 977 (NNTP) by deleting periods previously added, but others not doing so, which may result in data corruption and even loss, this option allows to control the sender side transcoding prior to the Mixmaster handover aiming at a reduction of that nevertheless still unpredictable risk. '<switch>: none' leaves the message without encoding (like JBN and QS do), '<switch>: body' duplicates all leading periods within body lines, '<switch>: end' appends a line containing a period to indicate the end of text, '<switch>: full' applies both those rules according to the RFCs ('transparency'). Example: 'O-Remailer-Transparency: Full'
M2N Active	Set this header in your message to override the mail2news activation preset. '<switch>: yes' means routing of a news posting through the mail2news gate, '<switch>: no' uses the exit remailer to post the message to the according newsgroups. Example: 'O-Newsgate-Active: Yes'
M2N Address	Set this header in your message to override the mail2news gateway address preset. This allows you to choose the mail2news gate on a per message basis. Example: 'O-Newsgate-Address: mail2news@dizum.com,mail2news@m2n.mixmin.net,mail2news-hashcash@bikikii.ath.cx'
M2N Number	Set this header in your message to override the mail2news gateway number preset. This allows you to choose the number of mail2news gates on a per message basis. With a number lower than the amount of available gateways a selection is done randomly. Example: 'O-Newsgate-Number: 2'

Take into account, that OmniMix in principle removes all headers starting with 'O-' from messages, that have to be anonymized. If you want to make OmniMix remove the 'Anon Switch' from normal messages as well, you have to specify that separately by checking the 'Remove Anon Switch Header' box.

There are clients that don't allow to manipulate the header section of messages. That's why OmniMix comes with a Body Header Integrator able to move an additional header text block from the beginning of an incoming message's body into its header section.

Ctrl_All_Header_Diverse

This text block has to start at the first line of the body containing the introductory string defined at the 'Header' > 'Body Header' tab (preset to '####_Extended_Header_Section_####') and ends with a blank line:

--------------------------------------------------------------------------------
From: John Doe <john.doe@domain.net>
Newsgroups: alt.test
Subject: Body header test
Date: Mon, 31 Dec 2007 10:24:27 +0100
Message-ID: <d50xi8qml2u0dl3vz1isey8g1sk3bs84sl@xyz.com>
X-Newsreader: NoGood/16
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

####_Extended_Header_Section_####
O-Anon-From: None
O-Anon-Send: Yes
O-Remailer-Chain: 0 0 0 borked
O-Remailer-Copies: 6
O-Newsgate-Active: Yes
O-Newsgate-Address: mail2news@dizum.com,
                    mail2news@m2n.mixmin.net,
                    mail2news@bananasplit.info,
                    mail2news-hashcash@bikikii.ath.cx
O-Newsgate-Number: 2

Dear reader,

please ignore this message. It's only a test.

Regards
--------------------------------------------------------------------------------

Header lines embedded in the body section are only accepted with 'flat' single part messages. With a MIME multipart structure it would be difficult to detect all occurrences of the extended header block within a message, especially if the introduction string is coded in some way, meaning a high risk of revealing sensitive information. If the intro string is found at locations outside the first body line, the processing is aborted, as this may indicate a message containing alternate text parts OmniMix isn't able to remove body header information from. Make sure, that the intro string doesn't comprise of characters that are represented differently in HTML, as this would render detection of this phrase in untypical locations impossible. Due to the mentioned risks you should avoid extended header blocks and incorporate your directives directly into the header section whenever supported by the client software.