How to make sure that the multiple pop3 clients download the same emails from the same email address

Question

We are building an application where user can send email to single email address, we want multiple servers to download the email using pop3. currently the multiple servers are downloading the same email multiple times.

How we can make sure that the same email can be downloaded only once? The email contains attachments.

Answer 1

You should either track message IDs or date/time - message IDs is more robust, that'd be the solution I'd look into first.