Zoho IP Address Blocked by Spamcop

Zoho IP Address Blocked by Spamcop

I'm getting this error when sending to some recipients.

4.7.1 Service unavailable; Client host [136.143.188.14] blocked using bl.spamcop.net; Blocked - see https://www.spamcop.net/bl.shtml?136.143.188.14

Please help to rectify asap.

Thanks.