Graph API Messages

Question

Hey,

I have a recurring request of emails in the name of a user. I then parse these emails to my needs.

The problem I am facing now is that all emails get requested all the time.
I am setting a custom property for these messages that it have already requested (''attachmentAlreadyRequested").

But at the point of my first request (https://graph.microsoft.com/v1.0/me/messages[...]) I cannot limit my resultset to the messages I did not read yet.

Or can I restrict my resultset so that I only get the messages that do not have the field ''attachmentAlreadyRequested" OR where ''attachmentAlreadyRequested" = false ?

Best regards