DFN mail support

Since 2012 the German Research and Education Network ( Deutsches Forschungsnetz , DFN) has been offering this service. With this the filtering of emails is no longer done decentralized at the various institutions but instead centralized at the DFN. This way only filtered mails and those checked for malware will be passed on to us. This saves us tedious maintenance of local filter rules and enables us to deploy new technologies as soon as they are introduced at the DFN.

Through this service the email undergo

• malware recognition
• spam recognition

among other things. With the spam recognition a "spam score" is being assigned as was done previously. A higher score indicates that an email is in fact undesired.

operating mode

The DFN mail support service has different operating modes for dealing with emails.We use the recommended operating mode, meaning in particular:

• Emails with recognized malware will be rejected
• Emails with a high spam score (>10) will be rejected
• Emails with a medium spam score will be marked:
  • The subject line will be prepended with "[Spam]"
  • The line X-Spam-Flag: YES will be inserted into the header.

The procedure varies only slightly from the previously used one. An overview of the changes is available at:
DFN mail support - overview of the changes.

notes

• Emails that are transmitted completely within the university are neither passed through the filtering of the DFN nor are they marked. They will still be checked by internal virus scanners.
• There is no automatic filtering out of spam emails at this point in time. Spam with a medium spam score is still being marked but will not be moved to the folder.