Have you ever experienced the dread of prematurely clicking the "send" button on an incomplete or unpolished e-mail message, or using "reply all" when you meant to reply only to the sender? Sure you have. This familiar experience is one reason IronPort Systems announced Wednesday its plans to buy PostX Corp., a provider of message encryption and recall software. IronPort, which has 450 employees in 25 countries, didn't disclose how much it plans to pay for 60-employee PostX.

IronPort, whose e-mail security technology is best known for combating spam, will by early next year integrate PostX's PxMail encryption capabilities into IronPort products, which the company says serve more than 350 million e-mail users worldwide. PostX's technology works with any e-mail software because it directs recipients to the Internet to retrieve their messages. Using IronPort's Web-based Email Security Manager in conjunction with PostX, which wraps e-mails in the equivalent of a digital envelope, e-mail recipients can access e-mails only after authenticating themselves to a Web interface.

IronPort also announced a new content rendering engine within Email Security Manager that can open and extract text and metadata from nearly 400 different e-mail attachment types, including PDF files and all Microsoft Office documents. IronPort also protects companies from e-mails leaving their network and has added PostX-developed lexicons, including a HIPAA-friendly one endorsed by the American Hospital Association, to IronPort's own pattern-matching algorithms that search for sensitive words contained in outbound e-mails that should be quarantined or blocked.

IronPort's acquisition comes at a time when companies are increasingly concerned about the exchange of sensitive information via e-mail. E-mail has also become a major channel for spyware, phishing attacks, and other security threats to enter company networks. Internet Research Group analyst Peter Christy describes the problem this way: "Your e-mail processing costs are now being dictated by spam, not the volume of useful e-mail to the business."

The PostX acquisition complements IronPort's existing technology, which should help with product integration. "PostX provides them a secure way to deliver e-mail over the Internet that's simple to set up and administer," Christy says, adding that PGP Corp., Voltage Security, and others offer similar technologies to PostX, but the integration with IronPort will make PostX more accessible to a larger number of e-mail users.

Accessibility is crucial to the adoption of security measures; if it's not easy for workers to use, it won't be used.