After I recieved one new email with 3 attachments, the flow has one successful run and I saw 3 new files uploaded to the target SharePoint library. This proves that this email with attachment trigger can handle multiple attachments.
But if you want to have an archive for email attachments in flow, I think this cannot be done so far. You could post this idea in the Flow Ideas forum, so it might be considered for future releases.
thanks for your answer. I cannot accept it as a solution since the idea is to build an archive with all attachments from an email. However, I created it as an idea like you suggested. You can find it here: