host mx.zoho.com[165.254.167.50] said: 541 5.4.1 Mail rejected by destination domain

host mx.zoho.com[165.254.167.50] said: 541 5.4.1 Mail rejected by destination domain

Hi,

we have a blog here http://www.mybubblyzone.com that send about 10 email a day to infomybubblyzone.com .
  1. Server IP: 151.236.220.136
  2. Server hostname: ns8-ew.ewake.it
  3. Return path: mybucomns8-ew.ewake.it
  4. From: wordpressmybubblyzone.com
  5. To: infomybubblyzone.com
  6. DKIM: ok
  7. SPF: ok
I've added this email (mybucomns8-ew.ewake.it, wordpressmybubblyzone.com) on spam whitelist section, but every email come back with this bounce:
  1. <infomybubblyzone.com>: host mx.zoho.com[165.254.167.50] said: 541 5.4.1 Mail rejected by destination domain (in reply to RCPT TO command)
Thanks,
regards