It looks like the answer to the question was given in http://www.wildapricot.com/forums/thread/1637.aspx
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If you
have members in your member list, you can use E-mail members feature. The
problems with the members you imported is that all of them have “Subscribed
to member e-mailings” set to No. This means that each member does
not allow to receive email from you and our system exclude them from target emails.
As far as I understand it is not what they
really set – this is just because of mass bulk import. To make
it possible to send e-mails to these members, you have to set “Subscribed to
member e-mailings” to Yes in their profiles. The fastest way to do it is to export
all these records, set the corresponding column in the Excel file to Yes and
import again. This will update the flag to all the members and you will be able
to send them emails.
Evgeny Zaritovsky,
Apricot's Kernel
Wild Apricot team