The Faculty of Arts and Science's (FAS) main e-mail server (HUSC) crashed unexpectedly yesterday morning, causing e-mail services to remain unavailable most of the afternoon.

The mail server stores and distributes all incoming and outgoing e-mail for FAS. The crash prevented Harvard faculty, students and staff from checking e-mail for more than five hours.

By 4 p.m., the Harvard Arts and Sciences Computer Services (HASCS), the computer support arm of FAS, had the system operating again.

HASCS staff believed no e-mail was permanently lost in the crash, although several more hours of work were necessary to confirm this, Coordinator of Residential Support and HASCS spokesperson Rick Osterberg '96 said last night.

"At around 11 o'clock, HUSC had a major, major crash, and everyone ran in here and immediately tried to reboot it, but it wouldn't come back up," Osterberg said last night from the machine room in the Science Center.

Around noon, HASCS contacted Digital, the company that sold the machines to Harvard and helps trouble-shoot major problems. Digital and HASCS agreed that the problem was in the system software.

HASCS rebuilt the system file using a more up-to-date system that Osterberg said will help with file recovery in the future.

When the system was brought back up around 4 p.m., HASCS discovered that a number of people's in-boxes had been corrupted and moved off the system. Around 7 p.m., HASCS was working to move people's in-boxes back to the system and expected to have the system back to normal around 10 p.m.

"It's definitely been a miserable day but it could have been a lot worse," Osterberg said. "We could have lost a lot more mail."

Today's crash comes on the heels of a series of problems HASCS has had this year in maintaining the e-mail system. At the beginning of the term, HASCS installed $300,000 in new servers to upgrade Harvard's e-mail system to handle a massive increase in e-mail usage.

Harvard's e-mail system has been plagued with problems this semester while HASCS staff have struggled to work out the quirks in the new system.

In November the problems become so severe that Professor of Classics and History Christopher P. Jones raised the issue in a meeting of the Faculty.

"Many of is who use e-mail regularly...know that the situation is not well. I would like to know...what amelioration we can hope for," Jones said