actually i'm not completly sure now. I thought so at first, because I had emailed them from both of my email accs, and go this msg
This is an automatically generated Delivery Status Notification.
Delivery to the following recipients failed.
accountadmin@ntreevusa.com
but, now i don't think they did block (ban) me from emailing me.
and i meant like they send my emails straight to delete/junk by banning it '-'
i just sent another email and it worked
afaik ;o