Difference between revisions of "UtterChaosEmail"

Revision as of 22:10, 22 October 2008

This page contains information on how to use the UtterChaos email system provided on Kemelin.

Webmail

Webmail is easily accessed by connecting to https://kemelin.utter-chaos.net/horde/

The more easily remembered http://mail.utter-chaos.net will redirect you to the secure URL.

Mail Filters

This section details the creation of server side mail filters using horde. The steps below provide an example of how to setup a SPAM filter. The creation of any other filter rules should naturally extend from the example.

Warning

If you have filters that are running from the old email system and they are not listed in the filter list as seen in the steps below, you will need to add them all now if you want them to continue to work. Once you've made any changes to your filters with the new system. The old ones will be deleted. Nybble has backups of the old filter rules if you need them.

At mail.utter-chaos.net, Expand the "Mail" Tag by clicking on the "+" next to the Icon.

Click the "Filter" Link under the "Mail" Application Tag

Click the "New Rule" Button to create a new Filter.

Fill out the Rule by using the one in the image below as an example. You should select the "Junk" or "Spam" folder that you created previously. Then click "Save."

To Make sure that your Mail Filters are running. Click on the "Script" Tab and then on the "Activate Script" button.

If you want to make it so that you don't need to Activate the new script when you make changes like you did above. Do the following:

Click the "Options" tab. Check the "Automatically update the script after each change?" box. Then click the "Save Options" button.

Additional filters can be added here as well. The filter matching program starts at the top and works its way down. It only applies the first rule that it finds. I would recommend not using the Whitelist Filter provided by Horde because any address placed in it will not go through any of your filters. If you want white lists for spam purposes, check the SpamAssassin Config section below

IMAP

This section specifies the appropriate configurations for an email client to connect to your email account on Siranna.

IMAPS

Kemelin only supports IMAP connections over SSL. This keeps your passwords safe and email archive secure.

1. Configure your client to connect to kemelin.utter-chaos.net on port 993 via SSL enabled IMAP. If your client does not support SSL, then you will need to find another client, figure out stunnel, or use the webmail services.
2. Configure your client to use password authentication (plaintext, not CRAM) and provide your username and password as needed.
3. If your client asks, Kemelin supports having messages and subfolders in the same folder. (Mozilla & Netscape ask this)

Setting up SMTPS

Kemelin will only relay messages from authenticated users. This method uses STARTTLS (SSL) enabled SMTP with authentication to protect a user/password login.

1. Configure your client to send email by SMTP.
2. Choose kemelin.utter-chaos.net as your outgoing mail server. The SSL/TLS port is 25. If port 25 does not work due to your ISP blocking it, use port 26.
3. Enable SSL for outgoing mail, and choose to always use SSL if appropriate for your client.
4. Choose password authentication (not CRAM) for SMTP, and supply your username and password to your client as appropriate.

SPAM

The antispam system on Siranna has support for a Bayesian statistical classifier. This classifier needs to be trained to identify SPAM and HAM (valid non-spam email). By default the system will try to learn what your SPAM & HAM look like based on the normal SPAM rules that are installed. This auto learning will only occur on new mail and will take take forever to learn well enough to be useful.

If you have saved lots of messages (both HAM & SPAM) in separated folders, Nybble has written a script that will make use of your piles of crap that you have kept. It is important that you train it on HAM and not just SPAM. In fact, it is recommended that you use at least as much HAM as SPAM to keep the classifier from flagging too much of your real email as SPAM.

1. ssh to kemelin.utter-chaos.net
2. Run 'learnspam.rb' at the prompt.
3. Answer the questions that it asks you.
4. Wait 3 to 20 minutes depending on how long since you last ran it.
5. 'logout' or 'exit'

The next time that you run 'learnspam.rb' it will remember the mail directories that you used last time. If you've added or changed mail directories since the last time you used it, you should answer "no" when it asks if you want to use the same directories for Ham and Spam again.

For those of you who can't stay logged in for the time it takes to let this run, here is a quick tutorial on how to use screen:

1. ssh to kemelin.utter-chaos.net
2. Run 'screen' at the prompt
3. Run 'learnspam.rb' at the new blank prompt.
4. Answer the questions that it asks you.
5. Once it has started learning, type '<ctrl>a' then hit 'd'
6. The screen will disappear leaving you with a prompt that says [detached]
7. 'logout' or 'exit'

at this point the learning process will continue while you do other stuff. When you want to check on it do this:

1. ssh to kemelin.utter-chaos.net
2. Run 'screen -r' at the prompt
3. Observe the progress
4. If everything is done, then type 'exit' until you are logged out else follow step 5 above.

SPAM evolves over time so I recommend running the 'learnspam.sh' script occasionally (monthly) or whenever it seems like it is missing lots of your SPAM or hitting lots of your HAM. Subsequent runs of the script should be faster than the first as the messages that it has already looked at before will be glossed over.

Wiping out the SPAM classifier

In the event that you wish to remove or restart the classifier from scratch, this is how you delete your classifier's database.

1. ssh to kemelin.utter-chaos.net
2. Run 'rm .spamassassin/bayes*' at the prompt.

Congratulations, you no longer have a SPAM classifier. The rule based anti-spam system will still be in place.

Playing with SpamAssassin's configuration

Those of you with the desire to tweak your anti-spam system will find the preference file located in .spamassassin/user_prefs

The default config file provided should explain some of the simple settings that you can edit. These include the threshold for tripping the SPAM flag for filtering, scores for various rules, and white-listing addresses.

Some of you may want to increase the score that the SPAM classifier gets. By default the highest contribution that it will give is 3.6 while 5.0 is the default threshold. If you want the classifier to flag a message as SPAM even if there are not other rules that are triggered on that message, you should increase the score for the classifier. Add the following line to your .spamassassin/user_prefs

score BAYES_99 5.00

This will allow the classifier to trip the threshold when it thinks that a message has a probability of being SPAM of >= 99%.

Rather than using the white lists that horde provides, I would strongly recommend using Spamassassin white lists instead. [1]

Adding:

whitelist_from *@utter-chaos.net

to your user_prefs would provide you with whitelisting of UtterChaos email addresses.