Message Traffic Management

StopIT® for MIMEsweeper for SMTP™ allows you to smooth out peaks in mail traffic volume and to protect internal mail systems from volume based denial of service attacks.

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itmodule section More Information:

  • What StopIT does

    StopIT® gives you all the benefits of MIMEsweeper for SMTP but with:

    StopIT® gives you all the benefits of MIMEsweeper for SMTP but with:

    • Improved Traffic Volume Management by providing filtering based on volume and message numbers transmitted in nominated time intervals.

    • Increased Resilience by providing management of incorrectly constructed SMTP transmissions.

    • Better Security by removing relay headers added by MIMEsweeper for SMTP and other servers as messages pass through the mail system.

    StopIT® can operate in Monitor Only mode.

    Let StopIT® monitor the traffic through your MIMEsweeper SMTP gateway to establish accurate representative maxima for normal message volume and numbers for all sending users and domains. Then use this information to protect your site from abnormal traffic patterns.

    Possible uses of StopIT® are when:

    • Your mail system users create very high volumes of low priority mail by mailing large messages to large mailing lists. StopIT® can identify unusual volume patterns, tag messages for parking by MIMEsweeper for SMTP, and for release by MIMEsweeper for SMTP at off peak times.

    • You want a report of the typical maximum volume or number of messages sent by a user or from a domain in a specified period of time (e.g. minute, hour, day).

    • Worm virus infection at one of your business partner's sites results in large numbers of infected messages hitting your site, constituting an attempted denial of service attack.

    • Your system suffers from mail loops as might occur if "out of office attendants" get chatting, or an internal recipient is automatically forwarding messages to an external account that fills up and generates error messages which are then sent back to the internal recipient.

    • You wish to conceal the content scanning mechanisms used on your outgoing e-mail, as well as the internal route that the mail has travelled to reach the intended recipients.
  • How StopIT works

    StopIT® examines every mail message received by MIMEsweeper for SMTP to determine the size and the address of origin.

    StopIT® examines every mail message received by MIMEsweeper for SMTP to determine the size and the address of origin. If a message conforms to the StopIT® volume rules, then it is allowed to pass on for content checking by MIMEsweeper for SMTP.

    StopIT® allows you to set the maximum volume (in Mbytes) and maximum number of messages sent from an origin (a specific user or domain) in a nominated time period. This is known as a StopIT® threshold for that origin. A specific user's number of messages and traffic volume can be included or excluded from the accumulated domain totals.

    An example of a StopIT® threshold is as follows: can send a maximum of 100 messages, totalling no more than 50 Mbytes per 60 minutes and include in domain total.

    When a StopIT® threshold is exceeded, a single inform message is sent to the system administrator advising which threshold has been exceeded. Messages from the origin can be tagged and processed using standard MIMEsweeper for SMTP functions or can be detained.

    StopIT® continues to monitor message traffic and offers two options for action when volume drops below an exceeded threshold. It can allow mail from the origin to flow again without StopIT® tagging or detaining it or it can keep blocking mail until an administrator intervenes.

    StopIT® is quite different to MIMEsweeper for SMTP's Park facility in two important respects; it operates on messages received over a period of time rather than on an individual message, and, it operates on message numbers not just size. Combine StopIT® with MIMEsweeper for SMTP's Park facility to get better control.