Thank you for considering Aspose.
Aspose.Email for .NET provides functionality to list and retrieve emails via Pop3 and Imap. If your email server is an Exchange then you can alternatively use Exchange related classes for the same purpose. Once downloaded, you can either save the fetched messages (along with their attachments) to disk or you can add them to a PST file for backup.
Please note, you have to implement your own logic for database insertion and retrieval processes because Aspose.Email does not provide such features.
Please feel free to write back.