Pure advertising or spam e-mails without phishing links and attachments are relatively harmless and only consume storage space.
This type of e-mail contains a link that looks very similar to a link to a valid page. In reality, however, the link leads to a website that is a replica of the original site. There, users are typically asked to enter passwords or similar sensitive information. The e-mail often states a reason why users should take this action.
E-mails with dangerous attachments usually contain a fake sender address, sometimes even known senders. The content is often cleverly worded to persuade users to click on a link in the e-mail or open an attachment. This can infect the system with malicious code and steal passwords or other information.
From April 9, 2025, spam evaluation and virus checking will be carried out by the DFN-Mailsupport service of our network provider DFN-Verein (Verein zur Förderung eines Deutschen Forschungsnetzes e. V.). All e-mail traffic with recipient addresses ending in @tu-dresden.de and @mailbox.tu-dresden.de will be routed via corresponding DFN servers, where it will be filtered and marked. Spam is evaluated by Spamassasin and Bogofilter. Three different virus scanners are used for virus checking.
Further information on the DFN-Mailsupport service can be found at https://www.mailsupport.dfn.de/
The following rules apply:
The spam marking is then evaluated in the TU Dresden Exchange. Messages with X-Spam-Flag: YES are delivered to the spam folder. How users can carry out their own evaluation is described here.
In the case of rejected e-mails, senders receive a corresponding error message and can rectify the problem if it is a regular e-mail after all.
Information on the processing of personal data can be found in the privacy policy for the email filter.
To improve the DFN's TUD spam filter, be sure to use the report button for Outlook and Thunderbird as described here: Reporting suspicious emails.
If the emails are received via mailing lists, the spam filter will not work. In this case, you must enter in the settings of the respective mailing list that only members are allowed to send to the list.
You can simply delete advertising e-mails. The e-mail programmes recommended by the ZIH (Outlook, Thunderbird, ...) allow you to sort e-mails into folders based on the spam rating. This allows spam e-mails to be sorted away automatically. This is even preset in Outlook and the Exchange web interface (but can be switched off if required). Users then have the option of reviewing and emptying this folder from time to time.
If you are unsure whether an e-mail is spam, you can first check whether the sender has signed the e-mail. If this is the case, it is a good sign that the e-mail is authentic. Otherwise, always consider beforehand whether you are expecting an e-mail with an attachment from the sender. Only then should you open the attachment without hesitation. Sophos is the latest anti-virus software available at TU Dresden as a state licence. It can help to prevent further damage and is able to prevent malicious access to your hard drive.
E-mail filtering is preset in Outlook and in the Outlook Web App (OWA). In OWA, this can be switched off or on again in the options under ‘Block or allow’. Here you will find instructions on how to set up a spam filter using inbox rules (OWA). In Outlook, spam e-mails are also filtered automatically and moved to the ‘Junk’ folder if necessary. You can also create a rule that uses the classification of the TUD mail gateway. The more stars (*) an e-mail receives, the more likely it is to be spam.
If e-mails seem suspicious or malicious to you because you suspect a phishing attack or malware in attachments, you can report them to the TUD-CERT. Reports are analysed promptly and countermeasures are initiated if necessary. In this way, the risks posed by malicious e-mails can be reduced and phishing websites, for example, can be blocked at an early stage. Further information can be found in the FAQ article "Reporting suspicious e-mails".
If the ZIH e-mail servers accept an e-mail for delivery, we must also deliver it to the user unchanged. This is required by the legal framework. In other words, from a legal perspective, there is no way for us to automatically delete recognised spam. This must always be done by the user or their e-mail programme themselves. Automatic deletion by the ZIH of messages classified as spam would interfere with the rights of the recipient and constitute a criminal offence of data alteration.
Sometimes users receive e-mails even though the users themselves are not in the address field. This can be for the simple reason that the sender of the e-mail has entered these users as the addressee in the BCC field (BCC: blind carbon copy). Addressees who are in this field will also receive the e-mail in question. However, whoever is in the BCC field is not transmitted with the e-mail. Therefore, if you are only in the BCC, you will only see the other addressees and not yourself.