If you received a suspicious email from Walmart but you did not place an order, it may be a phishing scam attempting to gather information, or your account may have been compromised.
While there is no indication that Walmart's systems have ever been compromised, many consumers are targeted by phishing and malware, which can trick consumers into giving their personal information (like their account password) to an unauthorized person.
Do not click on any of the links in the email.
Check your statements to see if any unauthorized charges were placed and monitor your statements
If unauthorized charges were placed, please contact your bank or credit card company to dispute the charges. Your financial institution is the best avenue to recover funds.