Mailing list
On the other hand, there are echo mailing lists people subscribe to. When a subscriber sends a mail to the mailing list, this mail is distributed (echoed) to all people who are on the list. The Software which manages such a mailing list sometimes offers options to the people who subscribe. Instead of getting each mail directly, they might want only one mail (per day). This mail then contains all the mails of that day. This is called a digest. Mails that come from people on the list might be handled differently from mails from people who are not subscribed to the mailing list.