EXIT109

Normally, as email is received by our mail server, the messages are collected and placed in individual mailboxes on our server. The messages remain there until you connect using your Mail Client (Outlook, Eudora or some other email program) to get your email. The mail is then transferred from our server to your computer. Once the mail has been sent to your computer, our server deletes its copies of the email.

The mail filter works on our server, intercepting email messages before they are placed in the mailboxes. Each email is checked for several hundred characteristics that are frequently used by spammers. As each telltale characteristic is detected, it is assigned a score rating. If an email has a total score of less than 5.0, the message is considered Ham (non-spam), and the filter places it in your individual mailbox.

If an email scores higher than 5.0, it is classified as spam, and the filter places a copy of the message on our server in a special storage folder, called the SpamBox. Messages remain in the SpamBox for a period of up to 15 days. Each night you will receive an email message listing all of the junk email that was placed in the SpamBox during the previous day. You can go to the SpamBox manager at any time to view and process the messages saved there. From the manager, you can:

View the contents of the SpamBox for a given day.

Deliver a copy of an email to your mailbox.

Add the sender of an email to your "allow" list.

Delete all SpamBox messages for a given day.

See Managing the SpamBox for more information.

Normally, you want to download only valid email. All messages that are marked as spam stay in the SpamBox, and only valid email is placed in your mailbox for download. You check the SpamBox periodically for the occasional valid email, have it delivered to you, and delete the contents of the SpamBox. However, if you wish, you can set the filter to also put copies of suspected junk mail in your mailbox. If you do this, you'll download those messages the next time you run your Mail Client. You can set your client up to place suspected junk mail in a separate folder, so you won't clutter up you InBox. Look at Setting Up Mail Rules for directions on how this is done.

Mail Filter Control Setup

Mail Filter Controls can be found Here. Filter Controls are divided into four categories - Mail forwarding, Virus Filtering, Junk Mail filtering, and Vacation Auto-Responder.

Forwarding All Your E-Mail

If you want to forward all of your email to another address (or addresses), you can do so here. All of your email will be forwarded to the address(es) you specify. The forwarding will occur after applying all of the virus and junk mail filters you specified.

Forward all my email to another address: Checking this box will activate email forwarding.
Forward To: Enter one or more email addresses in this box. If you enter more than one address, separate them with a blank space.
Keep a copy in my mailbox.: If you select this option, a copy will be sent to your InBox. If not, ALL of your email will be forwarded to the recipients you specify. No mail will be kept in your mailbox here.

Virus filtering controls

Virus filtering scans an email for attachments and embedded scripts. If an attachment of a type that can be run as a program under Windows is detected, the name of the attachment is changed, in such a way that accidentally opening the attachment will not allow the program to run. This filter is not a substitute for a good anti-virus scanning tool like Norton, or McAfee. This filter is not effective against viruses that target Apple computers.

The virus filter also has an option that will remove embedded javascript or vbscript programs from an email.

Enable Virus Filtering: Checking this box will turn on virus filtering
Remove Javascript from email: Checking this box will remove all javascript from an email.
Remove VBScript from email: Checking this box will remove all Visual Basic scripting from an email.
Treat Zip file attachments as dangerous: Zip files (compressed archives) are not normally treated as potential virus carriers. Selecting this option will add zip files to the list of dangerous attachments.
Send me a copy of emails with suspected viruses: Normally, emails with suspected viruses will remain in your SpamBox. Selecting this option will also send you a copy of any suspicious email

Junk Mail Filter Controls

When enabled, the junk mail filter scans all incoming emails and attempts to determine if they are valid email, or junk mail. All email that is classified as junk will be saved on our server, in an area called the SpamBox, for a period of up to 15 days. The following controls determine the operation of the junk mail filter

Enable Junk Mail Filtering: Checking this box will turn on junk mail filtering
Empty Spambox after ... days: Select the number of days you wish to keep items in your SpamBox. You can choose from 1-15 days. Spam messages older than this interval will be removed each night.
Use Bayes Statistical Filtering: Checking this box will enable Bayesian statistical filtering. This is not a "set and forget" option. Read the section on Bayes filtering before you decide to use this option.
Treat Bayes 99% rating as spam: Checking this box will cause a Bayes spam probability score of 99% to be sufficient to classify an email as spam (it is recommended that you not use this option until you have fully trained the Bayes classifier.
Do NOT send Daily Spam Reports: Checking this box will turn off nightly Spam email summaries.
Send me a copy of all detected SPAM: Checking this box will deliver a copy of the detected spam email, in addition to placing it in the SpamBox. Generally, this option is used when you first enable junk mail filtering. It let's you see if any real email is being classified as junk. You can accomplish the same effect by checking your SpamBox frequently. Generally, this option should be turned off.
Only accept mail from confirmed senders: Checking this box will only accept mail from confirmed senders. A confirmed sender is someone who is listed in your "Allowed List". If someone else sends you an email, the message will be held temporarily and an email requesting confirmation will be sent to that person, asking them to reply to that email. Once they reply to the confirmation request, they become a confirmed sender. The original message from them will be sent to you, and all future messages from that sender will be delivered immediately.
Allowed List: All email addresses (joe@abc.com) or domains (abc.com) listed here will bypass the junk mail filter. Enter only ONE domain or email address per line.
Block List: All email addresses (joe@abc.com) or domains (abc.com) listed here will always be classified as junk by the mail filter. Enter only ONE domain or email address per line.

Using Bayes Statistical Filtering

The Bayesian classifier tries to identify spam by looking at what are called tokens; words or short character sequences that are commonly found in spam or ham (non spam) email. In order to accomplish this, the classifier must be trained with at least 200 ham messages and 200 Spam messages before it will begin to classify incoming email. This is done automatically when you start using it. Depending on your normal volume of email, it can take anywhere from a few days, to weeks, or even months before the classifier is trained. Generally speaking, it takes much longer to receive 200 ham messages, than 200 Spam messages.

When first turned on, it will scan all new incoming messages. If a message has a spam score greater than 10, the classifier will automatically "learn" that message as Spam. If a message has a spam score less than 1, it will automatically "learn" that message as Ham (not Spam). If the Bayesian classifier has learned 100 messages that have the phrase discount medications and was "told" that those are all spam, when the 101st message comes in with the words discount and medications, the Bayesian classifier will be pretty sure that the new message is spam and will increase the spam score of that message.

When properly used, the Bayesian filter can increase the effectiveness of Spam detection to between 90% and 100%. In order to accomplish this, it needs you to help by training it and correcting its mistakes.

Setting up the Bayes Classifier

To turn on Bayes filtering, go to your Mail Filter Controls and check the box labeled "Use Bayes Statistical Filtering." You must have "Enable junk mail filter" checked before you can enable Bayes filtering.

The Bayes filter will begin to train as you receive messages. It takes 200 ham messages and 200 Spam messages before the filter will begin classifying email messages. You can view the training progress from within your Mail Filter controls, in the line below the Bayes option. It will show you how many spam and ham messages it has seen.

You can speed up the training process by feeding both spam and non-spam messages to the filter as explained below.

After you have trained the filter, you can optionally turn on the "Treat Bayes 99% rating as spam" option. This will cause the email filter to consider a bayes spam score of 99% to be sufficient to classify an email as Spam (be careful with this option. It's accuracy depends upon how well you have trained and corrected the classifier).

Training the Bayes Classifier

In order to achieve the best results, the Bayes classifier needs to be trained to identify both Spam and Ham. Occasionally, it will incorrectly identify an email. When this happens, you need to retrain the classifier by feeding it the suspect email, thus informing it of the email's correct classification.

If you fail to "train" the classifier, it will still improve the ratio of caught spam. The improvement will only be a few percentage points. After training, however, the classifier can improve spam detection to almost 99%.

For ham (valid email) that has been classified as Spam, go to your Spam Manager. If you see a valid email that appears there, check the "ham" checkbox for those messages, and click Submit.
For Spam messages that get through the Spam Filter, there is currently only one way to feed that information back to the Classifier. That is via our Webmail client. You have to do the following before you check your email with Outlook, Outlook Express, Eudora, or any other PC based mail program.
Go to our Web Mail program. Login with your username and password. In the list of emails, check the box to the right of each spam that you see, then click on the red "Spam" icon near the top of the screen. The messages will be sent to the classifier as Spam, and will be removed from your InBox.
You can also use Web Mail to train the classifier for non-spam emails. Once you have fed all Spam emails to the filter, the remaining emails should be all ham. At this point, click on the top checkbox in the extreme right-hand side of the message list. This will select all remaining messages. Now Click on the green "Ham" icon. The classifier will learn all of these messages as ham.
Note: This is a great way to initially train the filter. On its own, the classifier will only learn messages with a spam score less than 1 as ham. By passing all ham messages to it, it will learn from ALL messages. This will speed up the initial training process.
It's OK to select the same message more than once. If the classifier has already learned a message as ham and you pass it to the classifier as ham a second time, it will ignore the request. Similarly, if you pass a spam message to the classifier more than once, it will ignore the subsequent requests to classify the message as spam.
If you make a mistake in classifying a message, don't worry. Just feed the message to the classifier with the correct setting. It will "unlearn" the old setting and re-learn the message with the correct setting.

We are looking at ways to train the classifier from within your mail program. Our goal is to have an email address (e.g. isSpam@exit109.com) to which you can forward a spam message that made it through our filters. Upon receiving the email, an automated program would use it to train the classifier that this message was indeed Spam.
That effort has been complicated by the fact that the classifier needs to be trained on the entire content of the original message, including the message headers. Eudora, and Microsoft Outlook have the capability of resending a message with all headers intact. Unfortunately, the most popular email program, Outlook Express does not have that capability.

We're attempting to find a way around this limitation of Outlook Express. For now, the Webmail site is the only way to feed spam messages to the classifier.

Vacation Auto-Responder

If you're going to be away from the office or home for a period of time, you can send an automated message back to anyone who sends you an email. In addition, you can also forward a copy of all messages you receive to another person. The following controls allow you to activate and configure the vacation auto-responder.

Activate Vacation Autoresponder: Checking this box will turn on the Vacation Auto-Responder.
From: This will default to your exit109 email address. It will be sent as the From address in all automatic responses. You can change this to any email address you wish.
Subject: This will be the Subject line sent in the auto-response.
Message: Type the outgoing message exactly as you would have it appear to the person receiving the auto-response message.
Cc: If you want someone else to get a copy of each email that you receive, enter their email address in this box. You will still have all messages you receive waiting for you when you return. Leave the Cc box blank, if you don't want anyone else to receive a copy of your email.

Managing the SpamBox

The SpamBox Manager can be found Here.
Your SpamBox is where suspected junk email is stored. It's kept there for a period of up to 15 days, and then deleted. Each morning, you will receive an email listing all of the suspected junk mail that was placed in the SpamBox during the previous day. If you are not receiving copies of junk mail in your InBox, this email will be the only notification that you will receive. For this reason, it's a good idea to check, and clear out your SpamBox several times each day.

When you first enter the SpamBox Manager, you will be viewing all junk mail that was received today. If you wish to look at the junk mail that was received on another day, click on the link for that date. A "Delete All" button appears directly under the date for which email is currently displayed. Clicking this button will delete all of the messages you are currently viewing.

Below the date selection controls, is a table contining the messages saved for the currently displayed date. If no email has been saved, the message "No messages found" will appear.

Each line of the table contains three checkboxes, "deliver", "allow", and "delete", along with the timestamp, sender's address and the message Subject. Checking any one or more of the checkboxes boxes, will mark that email for special processing. In order to process any marked messages, you must click on the "Submit" button at the bottom of the page.

SpamBox Controls

The following controls help you to manage the contents of your SpamBox.

Delete All: Will delete all SpamBox messages that are displayed for the currently selected date. Generally used after you have viewed and processed all messages for that day, and you want to delete ALL of the remaining messages you see.
deliver: Checking this box will mark the message for delivery to your InBox. Once the message(s) are delivered, you still have to run your email program to retrieve them.
allow: Checking this box will mark the sender of this email for addition to your "allow" list. The junk mail filter will not process emails from people in your allow list.
delete: Checking this box will mark this message for deletion. You can check delete in combination with deliver and allow. Deleting a message is always performed last by the SpamBox Manager.
Submit: Clicking this button will process the "deliver", "allow" and "delete" requests that you have previously checked. No requests will be processed unless you click "Submit".

Setting up Mail Rules

You can direct the mail filter to send you a copy of all suspected junk mail that it places in the SpamBox. This is a good idea if you're using the mail filter for the first time, or if you're the type of person who just wants to know what's going on. Each time you check your mail, you'll see all of your email, including suspected spam. You can quickly identify real email that was misclassified as junk and use the SpamBox manager to add that particular person to your allow list, so future emails from that indiviual will always pass through the filter.

Unfortunately, getting copies of all junk mail and all real mail, will generate a large amount of clutter in your InBox. You can avoid this clutter by placing all suspected junk mail in a different folder. All mail programs, Outlook, Outlook Express, Eudora, and Netscape provide you with mail rules that will look for some pattern in an email, and process the email differently if that pattern is detected.

When the mail filter suspects that an email is spam, it modifies the Subject line of that email by inserting (SPAM) ahead of the original subject. You can configure Outlook, Outlook Express, Eudora, and Netscape to detect the (SPAM) pattern and put that email in a separate folder. This will remove the clutter from your InBox.

Click on the links below for instructions on setting up mail rules for: