By making it easier to contact you! I received an email my Mailbox would be deactivated. I really don't know what type I have now.
Please contact me
510th
ranked

That email is fake. It was most likely sent by scammers trying to get your account information. You can just delete it.
For more information, please visit our help article: help.yahoo.com/kb/yahoo-account/SLN2091.html