Correct now, I'll solve the problem, thank you.
Feb 27 08:06:47 security opendkim[7249]: mail._domainkey.iwebhosting.com.br: key data is not secure: /etc/opendkim/keys/iwebhosting.c$
Feb 27 08:06:47 security opendkim[7249]: A4D561BC8C: error loading key 'mail._domainkey.iwebhosting.com.br'