Email accounts: last access and reports

As a Web-Hosting Provider, I would like a way to store and view information about when an email account was last accessed successfully and by what method (pop, map, or webmail) so that clients can find and delete abandoned email accounts to save space on their hosting servers and in server backups.

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A way to store information when an email account was successful last accessed (pop, imap or webmail). In this way it is possible to show abandoned accounts (example: employee of a company that was dismissed, but forgot to delete the email) and inform the client, who can delete the account, save space in their hosting account and also in server backups.

It would also be interesting to have a report with data about the email accounts, such as: when the account was created, when it was last accessed, allocated size and space in use (with percentage). The accounts abandoned for more than "x" days, display with background in different color, for example.