Cannot send message; recipient not accepted by user once I installed eM Clinet

I just set up eMClient and am running into a problem I haven’t had with Win 8 Mail or Win 7 Mail. This happens with every single email which used to send ok. Any ideas?

Whenever I try to send an email I get:
11:27:22 AM MailExceptions.ItemOperationException: Cannot send message (Email recipient not accepted by the server.)
11:27:23 AM eric@thisnthat.org [SMTP] Sending messages: Recipient address ‘smhanson@twcny.rr.com’ not accepted with reason:
11:27:23 AM "([192.168.1.8]) [184.153.239.206]:54153 is currently not permitted to relay
11:27:23 AM through this server.
11:27:23 AM "
11:27:23 AM MailExceptions.ItemOperationException: Cannot send message (Email recipient not accepted by the server.)

In the first place please open the account settings and tick the option “Server requires authentication”. Let me know if it helped.

George,

Thank you so much! It worked1

Eric