The email client, which has just been launched in public beta, is based on Firefox and Thunderbird - Mozilla's its email client. It also uses Mozilla's Gecko browser engine according toScott MacGregor, one of Postbox co-founders.
MacGregor was also one of the two Mozilla employees who headed Thunderbird development efforts before then-CEO Mitchell Baker pulled the plug on the email program.
Thunderbird was eventually shunted to spin-off Mozilla Messaging. MacGregor left Mozilla in autumn 2007.
Available in versions for Windows XP and Vista, as well as Mac OS X 10.4 and 10.5, Postbox is at root an email client with added functions, said MacGregor. "It's aimed at empowering people to do more with their email on their desktop," he said.
Among those features, MacGregor called out the integrated indexing and search, as well as something called the 'Compose Sidebar'.
Although Postbox's search function resembles Desktop Search, the Microsoft-made desktop search tool built into Windows Vista and available as an optional download for XP, MacGregor said that his application shows results "inline with the data that you're using. You see the results directly within the e-mail client". Desktop Search, on the other hand, shows results as a list on the Windows desktop, or within Windows Explorer.
"The sidebar lets you drag content right into messages," MacGregor added, referring to the Compose Sidebar. Available beside the message composition pane, the sidebar shows such things as attachments, photos and links located with a search; those items can be added to a new message by dragging-and-dropping.
"We also give the ability to browse attachments, and once you find one you're looking for, repurpose that content in another message, or elsewhere," said MacGregor. Postbox provides ‘connectors' to share emailed content with a variety of web services, ranging from Facebook to Twitter.
Although Postbox is based on Mozilla's open-source code, MacGregor wasn't willing to say that the service itself would also be open-source. "It's too early for us to know right now," he said, adding that the self-funded firm is still trying to decide on a business model. "We're going to use the beta to flesh that out," MacGregor said.
Postbox boasts other former Mozilla developers, including co-founder Sherman Dickman, who was the director of product management for Mozilla and Seth Spitzer, a software engineer who worked on Firefox.
The public beta, which can be downloaded for free from Postbox's site, will lead to a Version 1.0, probably by spring, said MacGregor. A Linux version is under development.
See also: Firefox 3.1 beta 3 delayed again