Distributed Denial of Service attacks: deliberate overloading of services via multiple sources with the goal of making these unavailable. By creating several thousand simultaneous connections they may require so many resources of a SMTP server that no more emails can be accepted.  Through this good emails obtain exactly the same priority as bad emails, but they are drowned in spam mails. Popular email server such as Sendmail, Qmail, Postfix or Mailmarshal are unable to distinguish these connections from each other.

Different filtering criteria do not block any emails with more or less success until a certain data amount has been reached. This leads to a huge administrative overhead for the OS because thousands of simliar connections must be handled at the same time. This slows down the whole email traffic and massively delays email delivery.

Nashire holds a patent on a highly sophisticated SMTP filter, that resides directly within the UNIX kernel. That allows for recognition of suspicious activity during message delivery at the earliest stage possible thus protecting you effectively from typical email-driven DDoS attacks. It's a reliable way to ensure you receive your important messages in-time – without significant delays.