Ensnare is a spam filter that monitors your POP3 accounts and filters out suspected spam messages. The spam is removed from your account, so that it is not downloaded into your email program. You can then review the filtered messages from the program interface and restore any of them if necessary. In addition to a built-in detection algorithm, Ensnare offers a combination of whitelists, blacklists, and an adaptive statistical filtering system. This allows you to exclude certain emails or completely block others.

MailMate is a spam filter that sits between your email program and your mail server. It acts as a local POP3 server proxy, that picks up all the mail from your ISP mail account, filters it and then passes it on to your email program the next time you check you your mail. The spam is automatically filtered and moved into a Junk mail area, from where you can review it, delete it or restore it. No mail is ever deleted without your consent. MailMate comes with a built-in keyword filter list that can be customized and can import your address book to create a list of friends that will be excluded from filtering. The filtering uses the message subject, sender and content of the email and can also filter by country, attachment and several other common spam techniques like Java applets, ActiveX content, IFrames and others.

Mailbox Guard lets you fight spam, junkmail and viruses before they get into your inbox. It scans and analyzes every message that arrives on your ISPs mail server and ranks it s risk in four categories: Virus, Spam, X-Rated and Bad Language. Depending on the risk factor of the content, each mail is color coded in red, orange, yellow or green. You can specify which level should automatically mark messages for deletion or choose messages individually. Selected items can then be deleted on the server, without being downloaded to your local PC. Additional features include background mail check, notification on new mail, plain-text preview and more. Mailbox Guard uses a built-in smart filtering engine that detected all spam messages during our test.

SpamAgent is a powerful email monitoring and filtering tool that allows you to get the email you want - and nothing more. It includes a comprehensive set of filters that block most spam and unwanted emails before they reach your inbox, and you can also add your custom entries to further improve the performance. SpamAgent runs silently in the background and monitors your incoming messages at a user defined interval. The program can filter email messages based on its sender, recipient, subject, body, as well as attachment type, forwards, and much more. SpamAgent offers to keep a list of friends, that will always be excluded from any filtering. Additionally, a built in reporting tool helps you fight back against spammers by reporting the unwanted intrusions directly to the spammers ISP. Unlike many other anti-spam tools, SpamAgent does not show the "good" email, but only acts as a spam collector, removing the spam from your mailbox. Even though, the spam is removed from your mailbox, it is actually deleted, unless you say so. SpamAgent allows you to review the filtered messages and optionally recover them before you decide to permanently get rid of them.

Norton AntiSpam works with any POP3 email program and automatically detects and flags spam as it arrives in your inbox and moves it into a special Spam folder, from where you can restore or delete any message. The program works directly on the TCP/IP level and does not reuqire you to change any settings in your email program. Norton AntiSpam can automatically learn from your email behaviour and will detect a high percentage of spam immediately after installation. You can also manually add new rules or add people to a never-block list to customize the spam filtering actions.

(STEVEN) is an anti-spam system that validates the sender of the email rather than relying on content alone to determine whether a message is spam or not. The program runs on your local machines and automatically replies to all emails it retrieves with a brief (customizable) message, asking the sender to validate the message by replying to it. Since the majority of spammers will not have a valid address, nor will they reply, it can eliminate almost all spam messages, without deleting any important mail. All messages, that have not yet been validated are added to a special queue from where you can review them, manually approve senders or delete them. Additional features include attachment blocking, web interface with statistics, sender blacklist and more.

Ella is an easy to use and very effective spam filtering system that integrates into Microsoft Outlook and automatically sorts incoming spam into special folders, keeping your inbox free of junk. Ella uses a fully automatic learning process that intelligently recognizes spam and requires no technical expertise or setup. Just follow the step-by-step wizard, point Ella to a few email messages that you consider good, and some that are junk and Ella will take it from there. In many cases you will have excellent filter results immediately after that, and if you have messages that slip through, you can simply click a button on the Outlook toolbar to tell Ella that you consider a message to be spam (or good) and the program will automatically learn from it and act accordingly in the future. Even though the Ella system is fully automatic, it is also highly adaptive and learns from your personal preferences, so that your spam filtering will be completely customized without the need for any complicated configurations on your end. Ella for Spam Control does not delete any email, but only moves it into spam folders, from where you can choose to delete it or review the messages later.

Webroot Spam Shredder automatically filters and quarantines spam and junk mail from your incoming email, before it reaches your Inbox. The program runs as a local POP server and auto-configures Outlook, Outlook Express and Eudora email accounts to filter all incoming messages. Spam Shredder works right away and does not require any manual filter set up. New filter settings can be downloaded automatically to keep up with the latest spammer tactics. In addition, you can maintain a Whitelist and Blacklist to identify email that should be immediately delivered or instantly deleted. The program offers 4 level of spam sensitivity, ranging from minimal to extreme. The quarantine messages are not deleted but initially kept in a quarantine location, from where you can review them , and restore selected messages if necessary.

Bongosoft AntiSpam 2004 is a challenge based anti-spam solution, that allows you to receive email from people you know, and sends a confirmation request to all other senders. Only if the sender replies to the confirmation mail with the password included in the message, will his email go through. Once confirmed, the sender does not have to go through the procedure again, and all subsequent e-mail from that sender are passed to your inbox. To make sure that the password is not read by a machine, it is converted to an image and sent as embedded picture or attachment. Unlike most other programs of this type, Bongosoft AntiSpam works directly on the TCP level and does not require you to run a local proxy. It works fully automatically with any email program and does not require you to change any settings whatsoever. The messages that are awaiting authentication are kept in your POP box and will be deleted if they are not confirmed after a customizable number of days. Messages from known senders or that were confirmed will automatically appear in your Inbox during normal email retrieval. You can also review the queue of pending messages and manually block any sender or domain by clicking a button.

Spam Buster is an anti-spam filter that works directly on your POP3 account(s) and marks spam messages, so they can be deleted before you download your mail with your regular email program. It uses a configurable set of keyword filters based on subject,sender, header and other email criteria. The program comes pre-configured with a large list of filters, and you can add your own or remove the filters that dont apply to your email habits. In addition, Spam Buster provides graphical statistics for top spammers, spam traffic by day of week, hour and more. It can also check mail automatically and notify you of new mail on the server.

Aggressive Spam Defense can keep your inbox clean by deleting unsolicited emails before they reach your inbox. It comes pre-configured to detect most common spam, and can further learn from your usage, and also easily be customized. An attractive interface allows you to assign weights to each of the detection keywords and phrases. In addition to email content, sender and subject, it can also filter based on the attachment type, allowing you to automatically delete potential email worms before downloading them. The program checks your POP account and displays a color-coded list of your incoming mail, marking all spam in red, good mail in green and all others in yellow. If you want, it can also delete spam automatically, so you don`t have to deal with it at all. You can preview each message, using a safe-preview and then choose to delete it or keep it.

Flystrike Spam Interrogator allows you to analyze e-mail messages before downloading them from the POP server. The program then assigns a score based on an inventory of tests to help you identify spam messages. Each message is then marked as good, possible spam or spam and the reasons for it are indicated along the side of the mailbox view. It includes several unique features like an option to compare messages based on a MD5 hash, creation of your personal IP block list, and blocking based on URLs found in the message (most spams contain some sort of URL). Additional features include optional complaint messages to the ISP, color coding of messages and more. We found it a little complicated to use and didn't like the interface that much.

Scam Sensor for Outlook automatically scans all email messages that you open and alerts you immediately if it detects or suspects a phishing scam. The program does not use any online databases, instead it analyzes the message directly, using a complex algorithm, and alerts you if the message is a fraud. During our review, we tested it with several common phishing scams (fake eBay, fake PayPal etc.) and it detected all of them.

Letterman is an effective anti-spam solution that combines pre-defined rules with customizable filter options that allow immediate filtering of spam out of the box, with the ability to customize the settings to match your personal email patterns. The program works with any POP3, Hotmail and Yahoo account, independent from your email program, so you don`t have to download messages first in order to filter them - spam is delete right on the server and never downloaded to your computer. Letterman offers a wide range of filtering options, including subject, sender, domain, country, foreign languages, and more. The built-in filters detected about 80% of spam during our test, and you can easily fin-tune them with a few clicks. Since Letterman works independently from your email program, you need to manage and delete spam before you download your messages, which adds an extra step to the mail checking process, but has the advantage of not downloading spam and potential viruses to your computer. Overall a very flexible, spam tool, however it requires constant fine tuning and interaction to keep your inbox spam free.

MailFrontier Desktop is a comprehensive anti-spam solution that integrates with Microsoft Outlook and automatically filters incoming spam into a special junkmail folder. The program combines several popular spam filtering techniques as well as anti-phishing features. It uses Bayesian filtering to automatically learn from spam messages, and a combination of blacklists and allowed senders to permanently block or allow certain recipients. In addition, MailFrontier also includes a challenge system that enables you to require a verification from the sender before his or her mail is accepted. Other features include detailed spam statistics, forwarding of messages to wireless devices, customizable content filter settings and more. MailFrontier Desktop delivers very accurate filtering straight out of the box, and can be easily tweaked to adapt to your personal email preferences.

Innovatools Email Control enables you to categorize and filter your email messages before downloading them to your email program. You can organize the mail by size, attachment, foreign language characters, and several other criteria, and also create your own filters based on common message properties like sender, subject etc. The program can also detect some spam by checking the sender domain against RBL lists and optionally delete it. Unfortunately, none of the filters allow you to set an associated action, so you are forced to review the items that were filtered into each category and then manually choose to delete them - which in our opinions misses the point of creating filters to begin with.

Vade Retro Antispam is a spam filter for Microsoft Outlook and Outlook Express that automatically scans incoming emails and sorts potential spam and viruses into dedicated folders from where they can be reviewed and deleted. The program`s filtering capabilities are based on a service that requires frequent updating of the filter definitions, which eliminates the need to create manual filters. We found the filtering results to be rather mediocre with only 70-75% of spam messages caught. Unlike most modern spam tools, Vade Retro Antispam does not have the capability to learn from misclassified messages, so there is no way for the user to improve the filtering results, other than hoping for improved filter updates - which are not provided during the evaluation period.

Spam Filter for ISPs is designed to be a front-end for your incoming SMTP server. It receives all emails addressed to your domain(s) and checks if the sender is listed in one or multiple DNS-based block lists; if not, the email is passed on to your main SMTP server. The administrator can configure which block lists to use, set allowed domains, filter by keyword and maintain a blacklist as well. SpamFilter runs on Windows and Linux systems, both distributions are included in the download.

Spam Monitor detects and tags unsolicited junk mail when you download it into your mailbox. It does not prevent the download of spam, but tags the subject line or headers of the incoming email, so that you can configure your email program to delete or otherwise process the suspected spam messages. The program offers a good set of flexible options that let you choose the level of filtering, as well as the use of external black lists. It further offers white/black list options, blocking by country and customizable network configurations. The program can automatically configure your email program to use Spam Monitor, it works on the TCP/IP level and works with any standard email program.

G-Lock SpamCombat is a complex anti-spam solution that combines Bayesian filtering with customizable rules. It scans the email messages while they are still in your POP3 account, and can automatically delete spam on the server, so that it is not even downloaded to your email program. Even though the email is deleted from your POP account, you can still browse through the deleted items and recover any mail if needed (similar to Windows Recycle bin). The Bayesian filter option allows G-Lock SpamCombat to learn from your actions, so all you have to do is mark a message as spam or good and the program automatically adjusts its filter settings to become more accurate. In addition, you can configure custom rules for messages that should always be deleted or accepted, remove viruses and malicious code and more. Additional features include statistical graphs, HTML tag filtering and more.