PSNA runs an email discussion list at portersquare@googlegroups.com. Any subscriber can post messages to this list. To sign up, email portersquare+subscribe@googlegroups.com.
If you haven't subscribed to such a list before, you might want to sign up for the digest version, which puts all the messages sent on the list each day in one message. This option cuts down on the e-mail traffic when the list is active, however you won't see messages until the end of the day.