It's been a while since we last provided an update about our anti-spam platform back at the beginning of February. Since then you'd be forgiven for thinking that it's all been a bit quiet on spam front, but rest assured we've definitely not been been resting on our laurels. Over the last two months our developers and network engineers have been busy beavering away at the configuration, code and script changes that will allow us to introduce the functionality promised when we last blogged about the subject. Fortunately the wait is almost over and you'll soon be able to get your hands on a wealth of extra features that we'll be introducing to the Manage My Mail tool in the PlusNet Member Centre. We've been listening to customer feedback, and many of the new features are things that our customers have been asking for a while now, even before the advent of Postini. The purpose of this blog therefore, is to give you an insight into some of the new tools that will be at your disposal, and how you'll be able to use them to improve the effectiveness of your spam filtering. We couldn't have really picked a more apt time to share our spam news either, with it being almost 15 years to the day since the coining of the infamous term. Did you know that it's been almost 30 years now since the sending of the first unsolicited bulk email. Ever since then it's been an ongoing battle with the spammers, so let's take a look at some of the weapons you'll soon be able to add to your arsenal.
Additional spam tagging options
Whilst not directly affecting the delivery of spam messages themselves, this new functionality will allow you to switch off the tagging of the subject line when an email is identified as spam by the system e.g. If you chosen to have spam messages moved to the 'Spam' folder then they will still be sent there, just without the [-SPAM-] string in the subject line. Subject line of an email with spam tagging enabled: [-SPAM-] Looking for Great Gifts? Rolex! Subject line of the same email with spam tagging disabled: Looking for Great Gifts? Rolex! This additional functionality was requested by the Usergroup last year using their Issue Tracker. The Issue Tracker is a tool used to raise suggestions for improvement based on feedback from customers across the Community, and you can see this particular item here.
Configure the aggressiveness of the anti-spam filter
The aggressiveness setting will allow you to control the thresholds that are used to determine whether or not a particular message gets marked as spam. There will be five levels of aggressiveness based around the spam scoring mechanisms explained here. The less aggressive you set the filter, the less likely the chance of a particular message being identified as spam. The more aggressive the filter, the more likely the chance of a particular message being identified as spam. When the changes are introduced the aggressiveness level will initially be set to 1 which is the most lenient setting (and is how your messages are being handled at present).
Move spam to a nominated mailbox
This option allows you to nominate a dedicated mailbox on your account to which all of your spam email will be delivered. It was another suggestion raised using the Usergroup Issue tracker last year. The mailbox of your choice will then act as a central repository for all of the spam sent to your account (irrespective of the mailbox it is destined for). As is currently the case with additional mailboxes, you will need to use separate login details to access this account. There's no mechanism for dequeuing messages to their intended recipient if they are found to have been identified incorrectly, however emails can be transferred easily between accounts using IMAP and a standalone mail client like Outlook Express.
Personal whitelist/blacklist
Arguably the most eagerly anticipated feature will be the ability for customers to create and maintain their own whitelists and blacklists. Whitelisting and blacklisting allows the user specify their own lists of blocked and approved senders. This can be done by specifying a specific email address or domain. 
A blocked sender is a domain or email address that you *do not* want to receive any messages from, whilst an approved sender is a domain or email address that you *do* want to receive messages from. Sometimes emails are identified as spam when they shouldn't be (false-postives). This has probably been the most common gripe since we began moving customers across to Postini. One way to prevent this is to whitelist the address a message is being sent from. This will ensure that it always get's delivered to your inbox unscathed, even if the system incorrectly identifies it as spam. Email from whitelisted addresses and domains will *always* be delivered to your mailboxes. It will never be identified as spam, will never be quarantined and will never be rejected by the Edge Protection filters (See below). Email from blacklisted addresses and domains will *always* be identified as spam by the system.
Optional edge protection
Edge Protection (also known as Blatant Spam Blocking or BSB) is a feature which is enabled by default. It's purpose is to automatically block the most obvious junk messages from reaching your mailbox. Our Edge Protection blocks well over 90% of all the messages that are sent to our network and greatly reduces the amount of spam you have to manage by stopping it from arriving in your mailbox in the first place. Messages that are sent to your account are first filtered by Postini. Postini add special headers to each email based on the number of spam characteristics a particular message exhibits. The email is then checked against the Edge Protection filters. If the Edge protection filters are confident a message is spam then it is rejected with a 571 Message Refused and is not delivered. Switching Edge Protection off is not recommended as it can greatly increase the volume of spam sent to your mailbox. Occasionally though, you may find that legitimate email sent to your address get's bounced back to the sender with a server 571 error. In circumstances like this, we recommend that you whitelist the sender which will allow the message to bypass the Edge Protection. We understand that whitelisting is not to everybody's taste though, so we've added this extra option so you have the ability to switch off *all* Positni filtering if you so desire.
Postini Quarantine
The Quarantine setting will allow you to switch off the PlusNet anti-spam filters and rely on our security partner Postini to filter and manage you messages. Quarantining spam works slightly differently when compared to the other options that will be at your disposal. Firstly, when an email is considered to be spam by Postini's systems it is quarantined on their servers. In order to access this quarantine you'll need to login to Postini's Message Centre using a unique username and password that will be provided when you activate the service. 
Similar to the 'Move to a nominated mailbox' option, the Positni Quarantine acts as a central repository for all of the spam sent to your account (irrespective of the mailbox it is destined for). Once logged into your quarantine area, you will be presented with a list of messages that Postini has identified as spam. Should you find any valid messages amongst this list then you can release them from the quarantine so they are delivered to their intended recipient. (This is particularly useful if you have children or younger members of the family who you wish to protect from offensive or pornographic spam email). If logging into Postini's website is a nuisance, then you'll be able to request that a Quarantine Summary is emailed to you each day. This summary lists the emails that have been quarantined during the last 24 hours and offers similar options to the web interface, allowing you the the option to release any messages that may have been identified incorrectly. NB: Email that is subject to Postini's Blatant Spam Blocking (Edge Protection) will *not* be Quarantined and will *not* feature in the Quarantine summary report. It can however still be switched off independently should any customers require this.
A note about the auto-delete functionality
One piece of functionality that we'll be removing is the ability to automatically delete messages that the system identifies as spam. Instead customers should select the option to move messages to the 'Spam' folder where they will be automatically deleted after 21 days. We actually changed this setting for most accounts back when we migrated the penultimate batch of customers in February.
What if I've opted out?
In preparation of these changes, we moved the final batch of customers to the Postini platform earlier this week. Over the last two months however there have been a handful of customers who have requested that they be removed from the Postini platform completely. We offered this opportunity mainly due to the inability to switch off Edge protection on a per user basis. As this will be possible under the new implementation we no longer expect there to be many situations where removal from the system will be necessary. Customers who have requested to be removed from the Postini platform will remain opted-out. Should any of these customers alter their anti-spam settings following the introduction of the new functionality though, it is likely to result in their domains and email addresses being migrated back to the Postini platform. This is due to the way the new system has been designed. If you have requested to be removed from the Postini platform in the past and wish this to remain the case then you should *not* alter any of your anti-spam settings using the Manage My Mail tool.
Decommissioning of the legacy spam filter
Part of the work to introduce the new anti-spam controls has involved the reconfiguration of our mail delivery software Exim to remove all references to our old anti-spam filters. Once the new configuration has been rolled out to the live servers, customers who have been removed from the Postini platform will be left without any server-side anti-spam filtering. This is likely to increase the volume of spam email that is delivered to these accounts. Customers in this position can re-enable Postini themselves by altering one of their spam settings as per the information above. If you have any questions, concerns or feedback regarding the new functionality, then please feel free to join in the discussion over on our Community Site Discussion Forums. We hope that you welcome the new changes and will post Further details to our Service Status feed later on today. NB: Please note that some of the screen grabs contained within the post are taken from early prototypes and may therefore contain some errors or discrepancies that will not be reflected on the live platform. Bob