Website hosting IP address was blocked by Zoho

I was setup phpmailer on my site, but "SMTP connect failed()" always happen when I pointing to zoho.

I tried on localhost, everything is fine, email sent perfectly.

So I called tech Support of my web hosting provider, he mention that wasn't able to ping zoho smtp. he assumed my web hosting provider IP address was blocked by zoho.

My question is that can be happen? If yes, how do I unblock my web IP address?

Thanks

Fauzan