If you want to contact IRS, use this webste.

Do not go to the website like http://www.irs.org or http://www.irs.com. They are for-profit website.

Also, IRS never call you or e-mail you about personal information. If you receive any calls or e-mails, it probably be involved with identity theft. I could not find IRS article about it, but IRS agents told me that they only communicated with taxpayers by mail.