I heard that Yahoo Mail has unlimited storage capacity abroad, and I wonder if it's the same domestically. So I went in to take a look. Unexpectedly, the first thing I saw when I entered the mailbox was "Yahoo Mail teams up with Yahoo Messenger, so you can write emails and chat without any conflict." I quickly gave it a try and found that it's pretty similar to Gmail. First, you can set your status as available, busy, invisible, offline, or customize your status message; on the left contact bar, it will show the number of online contacts. Clicking will pop up the contact list where you can perform contact addition operations, and clicking on a contact allows you to chat directly; when a new message arrives, the mailbox will pop up a yellow tab to remind you that you've received a message from a friend; when you're writing an email, if the person happens to come online at that moment, a notification will appear at the bottom of the page...