What means this [Steam mail]

In 2 days i received 3 of this emails, what this email mean? Is due to login in websites using the steamaccount?

Dear Steam User,

This is an automated message generated by Steam account administration. It is being sent in response to a query made by a Steam user to discover all account names associated with this CD-key.

Steam account name: XXXXXX

If you requested this query, please use the above account name to log in to Steam. If you cannot remember your password, click on the “Retrieve lost account” button on the Steam login screen.

If you did not request this query, please ignore this message – users cannot gain access to your account via the Find Account By CD Key process without access to your email account.

To further safeguard your account please read the following FAQs.

E-Mail Verification
Account Security Recommendations
The Steam Support Team
http://www.steampowered.com