There are a number of possible explanations for why verification codes don't always arrive. Read through the list of the most common causes, and see if any of them apply to you, or use our troubleshooter to help guide you.

If you can't sign in to your Outlook.com, Hotmail, Live, or MSN email account, or you're not sure how to sign in or sign out, here are some solutions.

Here's an example of how to use VLOOKUP. =VLOOKUP (B2,C2:E7,3,TRUE) In this example, B2 is the first argument —an element of data that the function needs to work. For VLOOKUP, this first argument is the value that you want to find. This argument can be a cell reference, or a fixed value such as "smith" or 21,000.

With message recall, a message that you sent is retrieved from the mailboxes of the recipients who haven’t yet opened it. You can also substitute a replacement message. For example, if you forgot to include an attachment, you can try to retract the message, and then send a replacement message that has the attachment.

Contact Support. For technical support, go to Contact Microsoft Support, enter your problem and select Get Help. If you still need help, select Contact Support to be routed to the best support option. Learn how to manage your Microsoft account security info and troubleshoot verification code issues.

Hotmail is now Outlook.com. Learn how to sign in to access your Outlook.com, Hotmail, Live, or MSN email account.

If you can't sign into your Microsoft account, most issues can be identified by our sign-in helper tool. The tool will ask you to enter the email address or mobile phone number you're trying to sign in with and check the details you provide.

Check the spelling of the name and the domain, e.g. rachel or rachael and .com or .co.uk. The account may have been closed. Learn more. If you see a password prompt, then your email is a Microsoft account.

All Outlook Data Files (.pst) and Offline Data Files (.ost) are listed along with the name of the account the files are associated with. If you cannot open your Outlook data file or suspect that the file is damaged, use the Inbox Repair tool (scanpst.exe) to repair errors in the file.

Detailed information about downloading and using Microsoft Authenticator in China. The Microsoft Authenticator app helps you sign into your accounts when you're using two-step verification.