Google is trying to persuade Gmail users to dump Internet Explorer in favour of its own Chrome browser or Mozilla's Firefox.
When users of IE6 reach Gmail.com, a "Get faster Gmail" message appears in the web-based service's menu bar. The message, in turn, links to a page on Google's website that touts Chrome and Firefox 3 as being "twice as fast" at running Gmail.
Last week, the Gmail site also displayed the message to users browsing with Microsoft's IE7, but Google has since discarded that version of the notice. Users running other browsers, including Apple's Safari and Opera Software ASA's namesake browser, haven't been shown the speed-up message.
Google currently lists IE7, Firefox 2.0 and later releases, Chrome and Safari as the only supported browsers for Gmail. Others, including Opera and older editions of IE, Firefox and Safari, can be used to access the e-mail service but aren't able to handle some of its features.
More than 21 percent of users who browsed the Internet last month ran IE6, according to web metrics company Net Applications Inc. IE7, meanwhile, accounted for about 48 percent of the browser market during November, with Firefox 3 in third place with nearly 16 percent.
Google has been aggressively marketing Chrome since it stripped the browser of its beta label earlier this month. A day later, for example, Google dropped Firefox as the default browser bundled with Google Pack application bundle and added Chrome in its place.