To receive the daily digest of SS-L, first subscribe in the normal way. Then send an empty email message to SYMPA@LISTS.ILLINOIS.EDU, with SET SS-L DIGESTPLAIN as its Subject.
If you decide you would like to revert to receiving individual messages immediately instead of the digest once per day, send an empty email message to SYMPA@LISTS.ILLINOIS.EDU, with SET SS-L MAIL as its Subject.