After send e-mail, message return:
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its recipients. This is a permanent error.
destination@domain.com, ERROR CODE :554 - 5.7.1 Service unavailable; Client host [136.143.188.16] blocked using spamcop.dnsbl; Blocked - see https://www.spamcop.net/bl.shtml?136.143.188.16
Check directly on SpamCop website, and the IP is the listed on BlackList.
Please, i need solved thi problem. Various messages was losting.