Answer:
Omitting.
Explanation:
To omit means to leave something out, or to fail to make use of something. It involves the removal of items that are not relevant for a particular purpose. For example is a business is reporting financial performance it may decide to omit details of a sports competition it hosted, because this information is not relevant.
Isabel segregates mails into those that are vital for her day-to-day tasks and those mails that are of little importance. She redirects mails of no significance to a junk folder.
She is omitting irrelevant mails.