Question : Can send to [email protected] but not [email protected]

The mail machine is called mail.test.com.  I can send to users only if it's [email protected] I can't send to [email protected], in my test.com zone file I have the following entry.

test.com. IN MX 0 mail.test.com

Also then I receive error e-mails and the following is probably the most important part.

554 5.0.0 MX list for test.com. points back to mail.test.com
554 5.3.5 Local configuration error

Answer : Can send to [email protected] but not [email protected]

Of course you are sending from the same server,
you have to set a test.com domain on the mail server to.. since the server is resolving the mx record for test.com and it SEEs that it doesn't have that domain on it it will throw that error.. think logically