---
type: source
title: "Overview of Blocked File Types in Emails"
tags: [email-security, spam-protection, virus-protection, university-greifswald]
related: [email-spam-virus-protection, blocked-email-attachments]
created: 2026-06-30
updated: 2026-06-30
sources: ["output/rz_uni_greifswald_de_dienste_allgemein_e_mail_spam_virenschutz_uebersicht_gesper.md"]
---

# Overview of Blocked File Types in Emails

This source documents the specific security policies regarding email attachments enforced by the Universitätsrechenzentrum (URZ) at the Universität Greifswald.

## Key Technical Policies
- **Real-time Scanning**: All incoming emails are scanned for spam characteristics and virus infections in real-time.
- **Immediate Rejection**: Emails that are not declared "clean" are rejected immediately. They are not accepted by the server, and the sender receives an instant notification explaining the delivery failure.
- **Attachment Filtering**: A strict list of prohibited file extensions is maintained to prevent the transmission of executable code, scripts, and potentially malicious database files.

## Blocked File Categories
The URZ blocks several categories of files, including:
- **Executables**: `.exe`, `.com`, `.app`, `.msi`, `.msp`, `.mst`.
- **Scripts**: `.vbs`, `.js`, `.bat`, `.cmd`, `.ps1` (implied by script categories), `.wsf`, `.wsh`.
- **Database/Project Files**: Microsoft Access files (`.mdb`, `.ade`, `.adp`, etc.) and FoxPro (`.fxp`).
- **Legacy Office Formats**: Older Office 2000 standards (`.doc`, `.ppt`, `.xls`) are blocked, implying that modern XML-based formats (`.docx`, `.pptx`, `.xlsx`) are permitted.
- **System/Configuration**: `.reg`, `.inf`, `.cpl`, `.msc`.

The full list of blocked extensions is detailed in the [[blocked-email-attachments]] page.