A pair of e-mail vendors this week will take aim at Microsoft Exchange with servers designed to give users alternatives to the back-end messaging platform.

Gordano is updating its cross-platform Gordano Messaging Suite (GMS) with features that support native Outlook client connections to the server and offer offline enhancements and improved synchronization. Start-up PostPath is releasing the first version of its Linux-based PostPath Server, which is designed to support Exchange's native protocols and look just like the Microsoft software on the network. Both vendors intend to provide users with cost and configuration alternatives to Exchange, which is becoming part of a much bigger collaboration and real-time communications platform Microsoft is developing.

"If your primary focus is e-mail, and you are interested in basic e-mail functionality, then any of these servers provide that," says Michael Osterman, president of Osterman Research. "In that regard, they do pretty much what Exchange does. There are some real advantages, particularly in those servers that have Outlook connectors, where you can maintain the desktop but change out the back end."

Gordano and PostPath compete with CommuniGate, IPSwitch, Mirapoint, Rockliffe, Scalix and Sendmail.

With GMS 12.0, Gordano has added an Outlook Message Transport provider for tighter integration between Outlook clients and the back-end server. Other client enhancements include Personal Folders files, which are PST-format, clientside storage that lets users work offline and get better synchronization support, especially with some mobile devices.

Gordano also has added what it calls Zero-Hour virus protection, based on Commtouch Software's Recurrent-Pattern Detection technology, which takes snapshots of messaging data and looks for patterns that may signal a virus is spreading. A centralized Commtouch Detection Center identifies emerging viruses by analyzing large volumes of Internet traffic in real time. Another addition is antispam technology based on the same Commtouch technology.

The company also has extended its External Folder API so the GMS Web client can hook into archiving, compliance and document management systems. GMS 12.0, which starts at $28 per user for 1,000 users, runs on Windows NT, XP, 2000 and 2003 versions; Solaris; AIX; and Linux distributions including RedHat, SuSE, Mandrake and Debian.