PLESK failure: Sorry._Although_I'm_listed_as_a_best-preference_MX_or_A_for_that_host,/it_isn't_in_my_control/locals_file,_so_I_don't_treat_it_as_local

This usually happens when the name of the server is NOT in the locals file for qmail. Check /var/qmail/control/locals (RPM) or /usr/local/psa/qmail/control/locals (standard) In addition to localhost, this file should contain the name of the server ( by using hostname command ). Sample: localhost ns1.mynux.net