The digest version is sent at least once a day and contains all that days messages in one email. This can greatly reduce the volume of traffic in your email box. The current email volume is over 100 messages per day. If you service provider limits the size of your disk space, your mailbox might fill up. You might want to participate using the newsgroup method described previously. .
Many users receive the digest version of the mailing list.
However those users send their unsubscribe request to the regular list and get frustrated. Make sure you are unsubscribing to the correct list. Do both if you are unsure. This feature should be used when posting information which you deem useful for months and years to come. It should not be used for chit-chat, general discussion, or off topic discussions.