As an administrator, what should you do to investigate why a user didn't receive a message sent 45 days ago?

Obtaining the message ID from the sender is an effective step in investigating why a user did not receive a message that was sent 45 days prior. The message ID is a unique identifier that can be used to track the specific email in question. By having the message ID, the administrator can look into the email logs to determine the status of the message, including whether it was delivered, bounced, or marked as spam, among other possibilities. This precise identification is essential for pinpointing the issue related to that specific piece of communication.

Verifying the user's account status could provide insight into any potential issues with the account itself, but it might not directly address the issue of the undelivered message. Similarly, using the Gmail recovery tool is typically more relevant in scenarios where an account has been compromised or messages have been deleted, rather than when investigating delivery failures. Checking spam settings for the domain could also be important, but without the specific message ID, it would be challenging to narrow down to the exact incident in question.