Spam filter

The incoming mail servers evaluate each incoming message to determine whether it is spam or not. This rating is entered in the message header. This rating is used, for example, by the spam filter of the KIT mailbox to move spam to the "Junk E-mail" subfolder of the mailbox.

Virus Scanner

Messages that contain viruses are rejected immediately.

Blocked file extensions

Messages that contain attachments with specific file extensions, such as exe, js, or docm, are rejected immediately.

Office macros

Microsoft Office documents in the old file format, such as doc or xls, can contain macros and are therefore potentially harmful. However, Microsoft Office documents in the new file format, such as docx or xlsx, cannot contain macros.

Messages with attachments that contain macros or macro-like content are rejected immediately. The sender receives a non-delivery report with the error message: "[EN] This server does not accept mails containing Office files with macros. Please use encryption or other means of transmission."

However, to send Microsoft Office documents that must contain macros to recipients in the KIT, they can be packed into a password-protected archive, for example.

Sending Office files (e.g. .docx, .xlsx) is permitted.

Sending Office files that potentially contain macros or macro-like content (.doc, .docm, .xls, .xlsm) or are in RTF format (.rtf) pose a significant security risk. Therefore, sending them to KIT-internal or external recipients is actively prevented. The sender receives a Non-Delivery Report with the following error message:

[EN] Office files containing macros are not allowed on this server. Please use another distribution channel or encryption.

If such files must be sent for organizational reasons and there is no alternative, such e-mails must be S/MIME encrypted or another distribution channel must be used. More information can be found in this article.