Only twenty-five sleeps to go.

The mail needs to be sorted so it can be delivered to the different sections. The section a piece of mail is delivered to can be determined by seeing who it is addressed to and looking them up on the section staff lists. If it's external mail it needs to be stamped with a date of receipt before it it delivered to the section. If it's internal mail it doesn't need to be stamped with the date of receipt.

Where does it say on the section staff lists if the mail needs to be stamped with a date of receipt?

It doesn't say that on the list. External mail needs to be stamped. If it's in an internal mail envelope then it doesn't need to be stamped; anything else does.

So I don't need to stamp the mail with a date of receipt?

Yes you do. You need to stamp the external mail.

How do I know whose mail needs to be stamped if it isn't on the section staff lists?

Everybody's external mail needs to be stamped. It doesn't matter whose mail it is.

Do we have a list which indicates whose mail needs to be stamped?

No. The source of the mail and the person it is addressed to are mutually independent characteristics of the item of mail. Stamp every piece of mail which is not in an internal mail envelope, without regard to the address.

I know mail for each person has to be stamped, but which sections need to have the mail stamped?

All of the them. All of the sections need all of the external mail for all of the people stamped with a date of receipt.

So if the external mail for all the sections get stamped, but the section staff lists don't indicate whose mail gets stamped, how do I tell if a piece of mail should get stamped?

Etc.
  ¶ 17:29