Can gmail api fetch mails from other accounts

The Gmail API can fetch emails from a Gmail account that the API client has access to, but it cannot fetch emails from other accounts without explicit permission.

Here are the scenarios:

1. Authorized user's account: The Gmail API can fetch emails from the account of the user who authorized the API client. This is the most common use case, where the API client is used by the user themselves to access their own emails.
2. Service account: A service account is a special type of Google account that can be used to authenticate API clients. A service account can be used to access emails from a specific Gmail account, but only if the account owner has granted the service account permission to do so. This is useful for automating tasks or accessing emails from a specific account programmatically.
3. Shared account: If multiple users share a Gmail account, the API client can access emails from that account if the users have granted the API client permission to do so. This is typically done by adding the API client's OAuth 2.0 client ID to the account's authorized OAuth clients.
4. Other accounts: The Gmail API cannot fetch emails from other accounts without explicit permission. This is a security feature to prevent unauthorized access to other users' emails.

To fetch emails from other accounts, you would need to:

• Obtain the necessary permissions from the account owner(s) to access their emails.
• Use the Gmail API's users.messages.list and users.messages.get methods to fetch emails from the authorized account(s).
• Handle any errors or exceptions that may occur due to permission issues or account limitations.

Keep in mind that the Gmail API has rate limits and usage guidelines to prevent abuse. Be sure to review the official documentation and guidelines before building your application.