When you're using gmail offline, you can only search email of no more than what you have set in "Recent message range"(e.g. 1 week, as my setting).
And if you set this "range" much long ago, the mail files in your local disk would be very large, and may use up your traffic (so it would be costly if you're using a China 3G mobile internet).
2010年4月2日 10:10:00
好像这个BUG也不是我上面描述的那样。
就算启用了offline，在连线的状态下，也是同样可以搜索早于一周的邮件的。（在离线的情况下当然不能要求它搜索到那么早！）