English L
English-L is a mailing list for people who are learning English as a Second Language (ESL). English-L is currently hosted on the University of Missouri-Columbia College of Education's server.
English Learner.com
offers English lessons by e-mail at three levels every week. It's completely free!!
TOEFL.org
TOEFL mailing list request form.
The English Learner Website
a free English newsletter every week that has three jokes, an idiom and a test in it
Yamada Language Center
a wide variety of English mailing lists.
tesol.net
subscribe to mailing lists at tesol.net or visit their links to other mailing lists. A must see!!