Mail Problem

[Poor_Knight]

Can someone tell me how to resolve this error? I sent an email from SSH. To some addresses, like gmail, I receive the email. To others, like my work email, no email arrives. This is a line from the log:

Sep 14 09:45:09 localhost qmail:
1158252309.014316 delivery 1331: 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._(#5.4.6)/

I do not know what causes this error...anyone?

Thanks in advance for any advise.