Would anyone have advice about hosting a listserv internally ?

We will have about 20 - 25 teachers/staff who will be discussing vocational

We do not host our web page or email. 

Perhaps some good "discussion" software ... Is blogging better ?

Just looking for the easiest/inexpensive  solution besides email for people
to discuss a common topic...

Many thanks,

Bill Clark, Austine School for the Deaf
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