Spam Recognition

Central Spam Recognition

Every mail from outside of the university goes through an automated check of trustworthiness and content. Based on

  • sender information (e.g. the delivering email server)
  • content information (contained phrases, links, ...)

a profile of characteristics will be created. From these characteristics the "spammyness" of the mail on a predefined scale will be determined. A higher score on this scale suggests a higher probability that the mail is of undesired nature.

The filter result will be noted in the transmission data of the mail which usually won't be displayed at full detail in mail clients. Further course of action depends on the respective score.

  • Messages with a low score (threshold of 8.0 at present) will be delivered without further action.
  • For mails with a higher score ("recognized spam")
    1. the subject line of the mail will be modified and the spam score inserted like this: "** Spam-Hits=1.23 "
    2. Other than that the mail will be delivered.

 

please note::

  • Emails that are being transmitted within the university will not go through the filter or receive any marking.
  • There is no automatic filtering out of spam mails. Even recognized spam will be delivered to the inbox as long as no further steps are being taken.

 

procedures regarding spam emails

Setting up spam filters

In many cases it seems desirable to not simply deliver recognized spam to the inbox, but to instead put it into a separate dedicated "spam" or "junk folder".
Due to legal reasons this configuration is not automatically done at the time of setup but must be done by the mail box owners themselves if they so desire.

The respective procedures and configuration options differ depending on the utilized mailbox service (Hermes or Exchange).

 

fine tuning of spam filters

In some cases it can be sensible or necessary to customize the recognition rules of the spam filters individually.