Spam is a difficult issue, not to say a nightmare, for all mail administrators. We have published articles about this in the past, and provide regular updates to assure users that the mail team is continually fighting spam.

CERN e-mail addresses receive up to 2 million spams each day. Spam falls into two categories:

  • the “obvious” spam (more than 90%), which is immediately suppressed and is never delivered to mailboxes or forwarded;
  • the remaining 10%, which is not as obviously detected and might occasionally contain some legitimate messages. For this reason the “not-so-obvious” spam mails are sent to the destination mailbox. When the destination mailbox is at CERN these suspicious messages are delivered to the Spam Folder, according to the user filtering level that is configured with the Spam Fight tool on the MMM website.

When a “mail forward” is activated, the 10% of the not-so-obvious spam are also forwarded (they might include some legitimate messages). It is up to the internet service provider or the home institute hosting the destination mailbox to provide its own special folder for suspicious messages. This same rule applies to users who have set their physical e-mail address (PEM) to their local institute or at home.

We would remind users that the “MMM forward” facility should only be used to forward incoming e-mails to another address temporarily. To forward mail on a permanent basis, users should set their PEM to their external e-mail address and avoid having two different mailboxes. (For more details, see the article “Users may need to request deletion of mailbox”.