Spam Filter (Frequently Asked Questions)

Why does the monthly spam scan report show spam blocked when I don't have spam filtering enabled?
Even before the server scans each message for spam it does some basic tests to see if the sender's server is blacklisted among many of the world's spam blacklist servers. If the sender's address or IP is listed as banned from any of these servers the email is still rejected even if you have spam filtering turned off. There's no need to worry about missing any email as a result of this as these rejects are always spam. This is usually pornographic or scam material sent from known spammer/scammer IP addresses.
What sensitivity should I choose?
This setting is up to you. Setting it to Low will catch the extremely obvious spam and have a near zero chance of ever catching a legitimate email. A setting of Medium will catch even more spam with a very slight risk of catching legitimate email. A setting of High does the best job at filtering out spam; however, has the potential of catching the occassional legitimate email.
What do the different handling settings mean?

You have 3 optional settings to "handle" the email the spam filter considers to be spam.
1. Conservative: This setting will still deliver all spam to you, with the subject line of the email marked with [SPAM]. You can easily then filter this email into a separate folder in your email application so you can review it at anytime. You can consider this a "Quarantine" folder.
2. Moderate: This setting will do intelligent routing of incoming email it believes to be spam. If the email is marked with a very high score it will be automatically discarded on the server; however, if the email is questionable and could possibly be a legitimate message it will still deliver it to your inbox marked with [SPAM].
3. Aggressive: This setting will discard all email it believes to be spam and not deliver any marked email to your inbox.
How do I configure the advanced settings?

The advanced settings give you no additional spam or virus prevention than the standard interface. The advanced settings are only for extremely fine tuning of the spam settings. If you are familiar with how spamassassin rules and scores work, you may feel comfortable with the advanced settings. If you are not, it is recommended you stay with the standard interface.
How powerful is this spam filter compared to others?
Quick Answer: More Powerful!.
Explanation: In multiple real-life tests the new filter has proven itself to catch more spam with less false-positives than the previous version we were running and has proven itself to catch more spam than other tested ISPs doing similar spam filtering. To learn more about how it does this and the features of the new spam filter please read below.
Email sent to me is being bounced back to sender with the message “blacklisted” in the reject message. What is this?
Quick Answer: Sender is blacklisted.
Explanation: One of the differences with the new software is blacklist handling. If an address tries to send to a customer that has such address blacklisted, it will automatically send a reject message to the sender telling them they are blacklisted. This practice is to follow email RFC’s (standard rules). To remove a sender from your blacklist, login to the spam filter and find the sender in your list of 'Blocked' addresses. Click Remove on the right to remove them from the list.
Should I still have local virus protection on my computer?
Quick Answer: Yes
Explanation: The email server scans all incoming email for virus attachments and gets a *very* high percentage. The definitions are updated every day and the scanning is very reliable; however, not all virus's arrive via email and there is ano 100% guarantee that the email scanner can find every virus. You can still receive virus's from web pages, instant messenger programs, even some virus's & worms propogate themselves automatically and require no input from you at all. It is highly recommended to keep up to date virus protection on your machine to have complete virus protection.

How does the new spam filter work?

The new spam filter actually resides on it’s very own servers now. Email from the internet is directed first to these spam filter machines. The spam filter processes the email for spam and virus’s and then hands it to the final destination (the pop3 server). The reasons for this are many, but 4 of the compelling reasons to do this is: 1) scalability: we can add more spam filtering servers as email load grows to handle the load easily 2) immediate load relief: the current pop3 server sometimes gets loaded when a huge bundle of spam comes in. Spam filtering is extremely cpu intensive and therefore requires a lot of attention from the server. During these huge spam loads in the past, sometimes customers experience very slow reaction time from the server when sending/receiving email. 3) Keeping ahead of the spammers is important. The new software will allow us increased ability to keep up with the new spammer and virus sending tactics to keep your email protected. 4) This new system will allow us to provide spam scanning for hosted domains. This is coming in the near future.

When email arrives on the new spam server it goes through 7 steps.

1. All incoming email is checked against RBL lists. 2 common ones are spamcop.net and spamhaus.net. Any sender originating from a blacklisted IP will automatically be rejected.
2. If the email has any attachments, it is suspended and processed by the virus scanner. The virus scanner opens up zip files, and scans the interior as well as all standard non-compressed attachments. Virus definitions are updated nightly to ensure the most up-to-date virus scanning ability. If a virus is found in the message, it is immediately removed and a message is dispatched toyou notifying you that the server found a virus in the message and removed it.
3. The sender and recipient of the message are scanned and compared to your allow and block lists. If the sender is in your allow list it will bypass spam scanning and be delivered. If the sender is in the block list it will bypass spam scanning and be automatically rejected back to the sender notifying them that they are blacklisted.
4. The email is then scanned using spamassassin rule sets. Spamassassin is one of the world’s best and most popular spam scanning server applications. Spamassassin generates a numeric estimate of how likely the email is spam and attaches it to the message
5. The email is then further processed using the Razor system which compares the message to a huge internet wide database of common and new spam. Razor also assigns the email a numeric estimate of how likely the email is spam.
6. The email is scanned by even more header and body checking techniques which may include custom rules to eliminate brand new or uncommon threats.
7. Now with scanning complete, the email is handed over to the pop3 server and available for the recipient to check the message. This whole process (depending on the size of the message) can take from 1 to 60 seconds to complete.