In Easy Invoice, it is possible for users to view their old invoices. All invoices that a user has viewed and/or dealt with are automatically stored in the archive.
The 'My Archive' option can be found in the overview of 'Purchase invoices' and is a standard functionality in Easy Invoice.
It is not possible for users to view another user's archive.
If you are interested in an archive that displays more than just your own invoices, consider using a dynamic archive. Read more about this in this article.
Tip: If you send an invoice to a colleague for information and want to be able to find it in the archive, it is important that the invoice is actually opened in Easy Invoice. In the background, it is then marked as 'seen', making the user part of the process.