Signup: Emails sent for "Is X a member" even when user not created..

[castaway]

This maybe a specific and somewhat minor issue to me using my local mail server - externally any email @mydomain is delivered to me (unless specfically aliased to something else).. but if I send to it internally, non-users get rejected.. thus foo@domain errored, user account wasnt created.. but space email got sent a "Is foo@domain a member"?

[castaway]

it occurs to me this will also happen if a user mistypes the domain of the email - so probably still needs fixing .. send to user first, and only to contact if that worked?