What is a mail client id

A Mail Client ID (MCID) is a unique identifier assigned to a mail client, such as an email client or a mobile app, by a mail service provider, like Gmail or Outlook. It's used to identify the client and its associated account(s) when communicating with the mail service.

Here's what an MCID typically does:

  1. Authentication: When a mail client connects to a mail service, it sends its MCID to authenticate the client and verify its identity.
  2. Session management: The MCID helps manage the session between the mail client and the mail service, ensuring that the client is authorized to access the account and perform specific actions.
  3. Tracking: The MCID allows the mail service to track the client's activities, such as sending and receiving emails, and to monitor its usage patterns.
  4. Security: The MCID can be used to enforce security policies, such as two-factor authentication, and to detect and prevent unauthorized access to the account.

Mail Client IDs are usually generated by the mail service provider and are specific to each client. They can be stored on the client device or in the client's configuration files.

Some examples of Mail Client IDs include:

Keep in mind that MCIDs are not the same as API keys or other types of authentication tokens. They are specific to mail clients and are used for authentication and session management purposes only.