To Upgrade and verify my E mail account

Hello,
I received the message as mentioned below, How to upgrade and verify my account. Please intimate.

Mahesh Patel
Mobile : 9825431622
E mail: ***@***

Dear Account User,
Your E-mail account will soon exceed its limit. Yahoo! recommends you upgrade and Verify your account to Prevent your email from being DE-activated within 24hrs . Please open the attachment for your account upgrade and verification.

This is to improve our service quality . We are sorry for the inconveniences

Property: Account Security

Sincerely,
Yahoo! member services