Mailshell Anti-Spam Desktop Universal Edition
Help Guide
Configuring Your Email Client
Using Mailshell Anti-Spam Universal
  General Options
  Outlook Express Options
  POP Proxy Options
  Approve Options
  Block Options
  Ignore Lists
  Advanced Options
Using Mailshell Anti-Spam Universal
Advanced Options

Enable Word Training

Enabling word training allows Mailshell Anti-Spam to analyze the presence of words in your spam and legitimate messages. This helps Mailshell Anti-Spam learn to better identify future messages as spam. Enabling word training does require more system memory.

    Maximum Number of Word Entries

    Word training involves tracking the frequency of words in spam and legitimate messages. Thus, increasing the number of words may increase accuracy but also requires more memory.

    Minimum Training

    For word analysis to be effective in identifying spam or legitimate messages, Mailshell Anti-Spam training on sets of spam and legitimate messages is required. Messages are trained automatically based on the messages from your approved and block lists and based on the auto-training threshold option. You can modify the value of minimum training to control when the word analysis data will be used.

    If the number is too low then the accuracy could be poor due to insufficient data. If the number is too high, then the training data will not be fully taken advantage of.

    Training Weight

    Training weight determines how much Mailshell Anti-Spam relies on word training to score a message. Selecting "low" will set a lower weight for local training data compared to global Mailshell-provided weight, while selecting "high" will set a heavier weight for local training data compared to global Mailshell-provided weight.

    A "high" setting may adversely affect the score if there is insufficient or improper training. The recommended default setting is "low".

Enable Rules

Mailshell Anti-Spam has built in rules that are used to identify spam messages. Enabling them improves accuracy but requires more time.

    Enable Extended Rules

    Mailshell Anti-Spam can download and use additional rules to help identify spam messages. This can help catch more spam, but startup time will increase and about 20 MB of memory is required.

Spam Scoring Timeout

You can configure Mailshell Anti-Spam to stop spam scoring if it takes too long. Although message scoring occurs in milliseconds, under extreme server load conditions scoring may take longer. If you wish to place a maximum bound on the time used to score your messages, specify it here. Timeouts happen on a message-by-message basis. Those messages that timeout will have a X-Spamcatcher-Score header based solely on the spam rules.

RBL Expert Options

    Enable RBL MultiHit

    If you have chosen to use multiple public blacklists, then each message is checked against multiple blacklist servers. If you want your messages to be scored based on the results of all queries, then you can enable this option. If you are confident in identifying a spam message based on results from just one of the blacklist servers, then you should disable this option.

    Disabling the option may improve performance because you will not have to wait for all blacklists servers to respond.

    RBL Timeout

    This allows you to set the maximum timeout in seconds before finishing all queries against public blacklists. The default timeout of 5 seconds is normally sufficient to allow for instances where the blacklist server may be slow to respond.

    If you wish to always wait for a response, then enter "0".

    Maximum Number of IPs to Query Against RBLs

    Each email message can pass through multiple mail servers with different IP addresses. If you have enabled checks against public blacklists, each of the IP addresses would be checked. You can specify a maximum number to be checked to control the amount of time taken for queries. This can affect performance.

    RBL Threshold

    Since checks against blacklists can introduce latency and a decrease in performance, this option allows you to do checks conditionally based on the score prior to performing the RBL checks.

Expert Options

    Auto Training Threshold

    This allows you to set a threshold for auto-training. If a message is scored at or above the high threshold, it is considered as spam and is then used to train all the enabled Bayesian modules (rules and/or word) except for sender and fingerprint of the message. If a message is scored at or below the low threshold, it is considered as legit and is then used to train all the enabled Bayesian modules (rules and/or word) except for sender or fingerprint of the message.

    Netcheck Threshold

    This allows running netchecks conditionally based on the score. Network is only queried if score is at or between the 'low' and 'high' range specified via this option. Networks can introduce latency and decrease performance, hence an option for conditional checks.