How I can empty my inbox folder or how I could delete all messages from inbox, I have 38,000?

The original version of Y.Mail lets you delete inbox messages only one page at a time. If you have LOTS of mails to delete (and I would certainly consider 38,000 to be lots), you might want to switch to the Beta version. In Beta, the inbox is one continuous listing, regardless of the number of emails. Therefore, you can delete the entire inbox in one shot. Simply right-click on any email, select "Select all messages", then click Delete. Once you're done, you can switch back to the old version of you wish.

Okay, First you go to inbox. Then here is a botton you can click that is named check all directly below the messages. Then you click delete whick is at the top of page just above the messages. Then it takes you to the next page once it deletes the first page. Then you do the same thing. Its like a cycle.

Down at the bottom of the page, on the left-hand side is the choice "Check All". This will check every message on the page. You then have to delete them. Unfortunately, I think you'll have to do that with every page full of messages. From now on, when you get a message you don't want, mark it as Spam, and Yahoo will put it in your Bulk bin. This will automatically be emptied every month. You don't have to even look at it. I haven't looked at my Bulk bin for ages, and ignore it completely. Just remember to mark all the spam as such.

Dang that is a lot! Sounds like you have not cheched in a long time. Haha have you ever seen Zoolander?!