SAN FRANCISCO, April 1 (Reuters) - It's not like Internet search service Google can't laugh at itself, but when an April Fool's joke got out of hand on Thursday, a real business plan was rumored to be a Web hoax -- and that was no laughing matter.
Privately held Google Inc. had Web message boards buzzing on Thursday over whether a new e-mail product, announced on Wednesday and meant to challenge Yahoo Inc. (nasdaq: YHOO - news - people) and Microsoft Corp (nasdaq: MSFT - news - people), was actually an April Fool's joke.
Google's announcement was questioned because of the U.S. No. 1 search service's unconventional sub-heading on a press release and because it also posted a fictional job listing seeking engineers for a "Google Copernicus Hosting Environment and Experiment in Search Engineering (GCHEESE)" lunar outpost.
Google's free e-mail service called Gmail, which will offer significantly more storage than Yahoo or MSN, "is not a hoax," said Jonathan Rosenberg, Google's vice president of products.
Google's unconventional March 31 press release announcing Gmail helped set Internet message boards alight because the sub-heading read: "Search is Number Two Online Activity -- Email is Number One: 'Heck, Yeah,' Say Google Founders."
"It is April Fool's Day. We were having fun with this announcement. We are very serious about Gmail," Rosenberg said in an interview.
Still, the Web was buzzing with speculation.
"It's going to go down in history as one of the biggest pranks ever pulled," wrote one message poster at Slashdot.org, which bills itself as a news provider for nerds.
That view was countered by others who noted the relatively low cost of storage and Google's registration of Gmail.com.
"The real joke was an advertisement for a job opening in 2007 at their lunar facility," another Slashdot poster wrote.
That recruiting ad -- which can be viewed by clicking on the Google.com link "Want a job that's out of this world?" -- details the benefits of working at Google's "Googlunaplex" location on the moon.
"The notion that we're actually opening a lunar office is consistent with the spirit of April Fool's Day, and, yes, it is a joke," Rosenberg said of the ad, posted around midnight Greenwich Mean Time on Thursday.
In fact, Google's informational site about Gmail, at www.gmail.com, was up and running Thursday during a test period with a small group of users.
According to Whois.net, an online service for researching domain name registration, Gmail.com does belong to Google.
