Microsoft loyalists could be forgiven for feeling a little smug after all of the publicity over outages and lost e-mails at online services run by archrivals Apple's MobileMe and Google's Gmail.

Microsoft, it turns out, isn't invulnerable. Some users of Microsoft's Office Live Small Business have also reported intermittent e-mail outages, according to interviews and postings at discussion forums for the Web service, which is used by more than a million small companies.

Through a spokeswoman, Microsoft acknowledged Tuesday that a "brief isolated" e-mail outage occurred last Friday.

But at least one user says he was told by Microsoft technicians that some of his e-mails were permanently lost.

"Outages you can understand, but the outright loss of data? They should be ashamed of themselves, being the biggest computer company in the world," said Joe Reilly, owner of Marine Wireless Internet.

Reilly said he is a paying customer of Office Live Small Business, which he uses to host his tech firm's Web site and provide his e-mail, through which he gets important messages, such as customer payment confirmations.

Reilly said he "became suspicious" when he did not receive "my usual 20-30 e-mails" on Monday morning. Confirming through his self-testing that e-mails were not being delivered, Reilly said he talked to Office Live's technical support, who told him that the service was "experiencing some issues."

First launched in 2006, Office Live Small Business is a service that allows small firms to design and host their Web sites, run their e-mail, an e-commerce store, Web advertising campaigns and more from a single service. Some of the services are free and some are provided for a fee.

E-mail for Office Live Small Business users is provided through Windows Live Hotmail.

The spokeswoman confirmed that Office Live Small Business and Hotmail customers were hit by a two-hour outage early last Friday afternoon.

"We are sorry to hear about this customer experience and are doing everything we can to help the customer restore his emails," she wrote in an e-mail. "This incident only affected a handful of customers and to our knowledge all customers' emails are being restored."

Not according to Reilly, who said he was reassured on Monday that mail would "trickle through in the next few hours." When that didn't happen, Reilly called back, and was told there was an "extended server outage" and that some customer e-mails had been permanently lost. After demanding a written confirmation, Reilly said he was referred to Microsoft's legal department.