Steam Guard email codes are sent to the last email address registered to your Steam account.
If you haven't received the Steam Guard email:
• Make sure the email address registered to your Steam account is correct
• Check your email spam filter and spam folder
• Add support@steampowered.com and noreply@steampowered.com to your email client's address book or trusted senders list
• Wait about 30 minutes for the email to arrive.
Email receipt may be delayed depending on the server load and processing time of your email service provider.
If you still haven't received the code after 30 minutes, try logging in again to request a new Steam Guard code.