Ability to block attachments from incoming mails

It would be nice to have a setting on the configuration page of the mail handler to allow administrators to choose whether or not attachments should come through incoming mails.

For example, whenever a user that has an image in the signature of their email reply to an existing issue (through email), the image will be added every time the thread is sent back and forth. We end up with a lot of unnecessary attachments on the ticket. If you have more users with images on their signatures bouncing through email to the same ticket, we'll have hundreds of unnecessary attachments.