Yandex mail server is blacklisted by DNSBL
If you sent a message from your Yandex mailbox and received a non-delivery report with one of these messages: “Client host [<IP_host>] blocked using bl.spamcannibal.org; blocked, See: http://www.spamcannibal.org/cannibal.cgi?page=lookup&lookup=<IP_host>”, “Client host [<IP_host>] blocked using dnsbl-1.uceprotect.net; IP <IP_host> is UCEPROTECT-Level 1 listed. See http://www.uceprotect.net/rblcheck.php?ipr=<IP_host>”, “Email blocked by SPAMCANNIBAL — to unblock see...”, “Email from <IP_host> is currently blocked by Verizon Online's anti-spam system”, “Recipient address rejected: Blocked by external RBL”, “Your host [<IP_host>] is blacklisted by dnsbl.sorbs.net. Currently Sending Spam See: http://www.sorbs.net/lookup.shtml?<IP_host>”, “Your server IP address is in the bl.spamcannibal.org database, bye”, this means that the Yandex mail server is on the DNSBL blacklist.
You can try deleting the Yandex mail server address from the blacklist manually by clicking on the link in the report. You can also write to us using the form below and forward us the complete text of the report you received.
Also, try contacting the recipient or his/her mail service administration by another method and report the problem.