Modifications to the University’s e-mail system, scheduled to be completed this morning, are expected to eliminate the server overload that has caused slowed performance during the past two months, Chief Information Officer Philip Long said.

Beginning last Thursday, Information Technology Services transferred approximately 5,000 e-mail accounts to newly purchased central campus servers, which progressively brought performance speed to normal levels, Long said. Though officials have not yet pinned down the reasons behind the servers’ previously poor response to high traffic volumes, Long said, they believe the problem may involve a flaw in the way Yale’s new Webmail service interacts with its operating system.

ITS officials must examine the data for several weeks before they can determine the account transfer’s precise effects, Long said. But anecdotal evidence suggests that performance has improved substantially since the modifications began five days ago, he said.

“Thursday and Friday showed radical reductions in the wait times on the server ends,” Long said. “Within a relatively short time we were able to add substantial capacity.”

Richard Morris, who fields user questions about e-mail at the ITS Help Desk, said students have stopped complaining about slow load times and disconnections over the last few days.

“I think people are happy that things are working again,” Morris said. “We’re going to be keeping an eye on things, particularly this week, to make sure there really is a change in performance.”

Last month, ITS reported that an unexpected 39 percent increase in disk space used by e-mail during the fall had severely degraded performance. A rash of viruses exacerbated the problem by flooding student e-mail accounts, Long said, though the frequency of the attacks has since abated.

The new servers have increased central campus capacity by a third, but officials are still unsure as to why the system failed so abruptly, Long said.

“What was really bothersome in the fall was, when we ran out of capacity, the service didn’t degrade slowly,” he said. “It’s like we fell off a cliff.”

An unpredictable drop in performance can wreak havoc on long-term maintenance plans, Long said, so ITS is examining more permanent ways to correct the problem. In the next few weeks, officials hope to pin down a potential flaw in interface between the Linux operating system and Yale’s new Webmail software. If their hypothesis is correct, a Linux update should prevent a sudden overload if the server is filled to capacity, Long said.

Current and future protective measures include architectural server rearrangements over the summer and outreach efforts intended to reduce the volume of e-mail that users store in their Webmail inboxes.

The new servers’ true test will come in the middle of the week, when the University experiences its highest level of e-mail traffic, Long said. Officials expect performance to improve by a third to match the corresponding increase in capacity, he said, but users may still experience different load times due to varying inbox sizes and e-mail programs.

Some students disputed ITS’ optimistic assessment of the account transfers, saying that they did not notice any performance enhancements over the weekend.

“I don’t have any connection problems, but it’s kind of slow,” Will Wilson ’09 said.

Others said they do recognize a change, even if taking e-mail for granted has kept them from appreciating it.

“I don’t really pay attention to the improvements, but when it doesn’t work, I get really mad,” Anna Goddu ’09 said. “I haven’t gotten really mad in a while.”

ITS last redistributed e-mail accounts last April. Users experienced some minor problems during that transfer, but ITS officials said they have not encountered any glitches this year.