MERCUR Messaging Server is a full featured SMTP/POP3/IMAP4 server for Windows NT, 2000 and XP platforms. It offers the necessary features to provide an efficient and effective communications medium. These include Security features using IP-Caching Firewall, check open relay database by using DNS, Remote Configuration via a Web Browser, Dial-Up-connectivity (Modem, ISDN-Card), dedicated connectivity (ISDN-Router) or connectivity over the network (Router) to your ISP. A built-in IP based firewall system protects your local mail system from unwelcome intruders. You can grant and deny the access to special IP-addresses and subnets. Incoming mail can be parsed for unwanted originator addresses and then rejected. You can protect your mail system against not allowed intruders and bulk mail senders, using the detailled anti-spamming options. These options are very important to decide who is allowed to use your server. Server names, domains and email addresses of incoming connections are checked by the system to find out what kind of permissions need to be used. MERCUR Messaging Server offers a interface to control third party anti-virus scanners. Whenever a new messages is received, the virus application will call via command line to locate virus infected attachments. If a virus is found, the infected message part will remove or save to quarantine directory. The MIME Filtering feature is used to remove special attachments, e.g. *.exe, *.vbs etc., from incoming email messages, defined in a list of file masks. This feature offers a usable extension to the anti-virus interface to filter not virus infected but also dangerous executable files. MERCUR Messaging Server supports secure password authentification for POP3 and IMAP4, as well as POP3-Login using APOP. Furthermore you can use subnet- or domain authentification for SMTP to RFC2554. It also supports international domain names (IDN) and is thus suitable for email addresses with special characters.