"... the person who receives electronic mail must forward such a document to [job title], who must also record it in the incoming mail register."
Does this mean that all incomming electronic mail i.e. all e-mail has to be entered into a mail register???
Answer: This text refers to documents of external origin that are necessary for the planning and operation of the ISMS (e.g., contracts, customer's specifications, industry regulations, change approvals, etc.), so only incoming external emails that contain these kind of information (either in the email body or as an attached document) have to be entered into the mail register.