I would like to request search capability in mail attachments in future versions, especially PDF attachments. Currently, I have to store the mail and then pull the attachment out and put it in the same filer in order to be able to search the PDF, which is really inconsistence, they often have different creation and modification dates since the attachment is newly created, making the whole process a pain to manage.
This has been discussed in other threads, and Christian has noted that the possibility of indexing attachments to emails is under consideration.