Thanks falko for the response...I trust when you help.
Well, i followed the steps on your post. I sent a test email and ive got this mail log:
Jul 23 03:26:13 myhomeserver postfix/smtp: 7E1418274: to=, relay=smtp.gmail.com[188.8.131.52]:587, delay=12, delays=0.24/0.02/12/0.64, dsn=5.7.0, status=bounced (host smtp.gmail.com[184.108.40.206] said: 530 5.7.0 Must issue a STARTTLS command first. e17sm2199998fke.18 (in reply to MAIL FROM command))
There is something missing on configuration in server handshakes and dont know how to fix it.