Distinct between two attachments provenant from two different mail


I have a problem please :
i have to download from outlook file attachment two types of file format (* .pdf) prevenant of two different mail (done)

the problem is that the two files contain two images (fax / mail) and I want to extract the same data so is there an activity or a method for the robot to know that it executes an email that contains a simple pdf or a pdf that contains the scanned fax.

So the use case will be like that : Get outlook message - save attachment - if the attachment prevenant from a mail do… , and if the attachment prevenant from a mail(scanned fax) do …