posting
n. Noun corresp. to v. post (but note that
post can be nouned). Distinguished from a `letter' or ordinary
email message by the fact that it is broadcast rather than
point-to-point. It is not clear whether messages sent to a small
mailing list are postings or email; perhaps the best dividing line
is that if you don't know the names of all the potential
recipients, it is a posting.