Unable to send message; Reason:550 sender-of-o52.zoho.com [135.84.80.217]:21485 DNSBL dnsbl.sorbs.net

Unable to send message; Reason:550 sender-of-o52.zoho.com [135.84.80.217]:21485 DNSBL dnsbl.sorbs.net

Hi

We can't send emails from our zoho account because zoho server with IP 135.84.80.217 is blacklisted in DNSBL dnsbl.sorbs.net.
Could you fix it? We need to send important emails

Thanks.
Regards