554 Sending address not accepted due to spam filter

[psyscrew]

554 Sending address not accepted due to spam filter:

When I send e-mail to: marilene@metaltampos.com.br
return this error:

Jul 12 15:49:46 mail postfix/smtp[13107]: 17A5A1D3012E: to=<marilene@metaltampos.com.br>, relay=server4.universonet.com.br[216.169.106.242]:25, delay=20, delays=0.05/0.01/1.2/18, dsn=5.0.0, status=bounced (host server4.universonet.com.br[216.169.106.242] said: 554 Sending address not accepted due to spam filter (in reply to MAIL FROM command))

What should be this?
How do I fix?

Thanks.
Lucas

[phoenix]

What should be this?

You need to contact the administrator of the receiving server and ask why they think you're sending spam, you should also check if your server is on any blacklists.

[psyscrew]

Ok! Thanks. My ip isn't on any blacklist. I'll try to contact the administrator of the receiving server.
Thanks.