SPAM FILTER/BLOCKER COMPARISON/EVALUATION CHART
|
Filter/Method |
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Postini™ (info link) |
SpamAssassin |
Client-Side Apps (ex: Norton Anti-Spam, AVG) |
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Characteristic/ Attributes |
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| Server-side? | Yes, all done on the servers | SpamAssassin "marks" the Subject Line " ***SPAM ... " SpamBox can be set to keep messages on server But note that usually the work of filtering "*** SPAM ***" subject headers is done by a Rule in your mailread application (and not effective in webmail, sadly) |
Yes, all done on server | n/a |
| Works equally well with webmail vs. installed application | Yes, all done on server prior to downloading to your inbox | Not really effective via webmail | Yes, all done on server prior to downloading to your inbox | Not effective via webmail, since the application is on your PC and webmail messages are not processed via local application |
| Web Form Filtering |
usually not effective | No | No | No |
| Safe Preview |
Yes, can safely preview in a web browser, messages/viruses never are downloaded |
SpamBox has an awkward way to set up access from email reader application | Yes, from BT "queue" | Usually no, depends on application |
| Virus protection | Yes, kept on server | Not explicitly | Not explicitly | Usually a separate application |
| Uses Acct Resources |
No, all done on server | SpamBox takes server acct disk space | Takes server acct disk space | All done on local PC |
| Gotchas/risks | ||||
| Whitelist (Trusted Senders) | Yes | Yes | Yes | Usually. |
| Ease of usage of spam control panel | Basic operations are easy and intuitive. We have some suggestions submitted to the developers for a smoother/more efficient user interface. | SpamAssassin does not offer many parameters to adjust. | Clunky but usable | Varies. |
| Success in combination with web form responses | Premiere postini accounts have the ability to whitelist SUBJECT lines; neither class of Postini accounts are able to whitelist source IP addresses. | No way to whitelist Subject Lines nor source IP addresses | Subject Lines are whitelist-able | We know of no client-side filter that whitelists subject lines or IP addresses. |
| Risk of aggravating sender | Postini is invisible to sender | invisible to sender | Challenge message is sent to the sender (to which they must reply in order to release the message to your inbox). This extra tranasction may aggravate your sender, altho many mail systems use this concept. If the sender is already on your whitelist, then no challenge message is sent. | invisible to sender |
| (Processing) Delay in receiving messages | Negligable | Negligable | Negligable | Negligable |
| Likelihood of missing real messages (i.e. real messages get trapped) | Little | Little to Moderate | Rare - it's more likely that the sender won't see or respond to the challenge message. | Little to Moderate |
| Likelihood of spam getting through | Little | Little to Moderate | Very rare- by quirk or very intelligent spammer | Little to Moderate |
| Ease of setup | Very easy - most users have no need to change parameters. | Moderate | Moderate (if you're familiat with Challenge-Response concepts, then it's fairly straightforward) | Installation hassles, custom parameter settings. Many complain of bad interactions with certain mailreaders, or system functions. |
| Cost | $2.50/month | Free | Free | Yearly Subscription (AVG is free) Sometimes ISP packages include a free Lite version |