ERROR_CODE :554, ERROR_CODE :5.7.1: Relay access denied

ERROR_CODE :554, ERROR_CODE :5.7.1: Relay access denied

I'm configuring the email account for XXX@catalogolibros.cl.
The problem is that emails are only received sometimes (generally only once), and after that they get bounced back with the error:

"XXX@catalogolibros.cl Invalid Address, ERROR_CODE :554, ERROR_CODE :5.7.1 <XXX@catalogolibros.cl>: Relay access denied"

I've tried this sending from another Zoho Mail account, and from a Gmail account, and both present this problem.

While testing from another Zoho account (XXX@espontanea.io), I also got:

"Your Mail Outgoing blocked. Reason :Daily Mail Bounce Count Exceeds Limit [ Bounce count=11 ]"

After which I kept going the ERROR CODE 554 and never got an email through to XXX@catalogolibros.cl again.

You can see a screenshot of the DNS configuration for catalogolibros.cl in http://i.imgur.com/zBHVLDw.png

Could you please tell me how to get the account working and receiving emails like it should?

Thanks.