======================================= Sendmail Server Spamhaus DNSBL rejecting all incoming email ======================================= Your sendmail.mc (freebsd.mc) is properly configured to use dnsbl and suddenly all incoming email is rejected. FEATURE(`dnsbl', `bl.spamcop.net', `"554 Rejected: Unsolicited e-mail from " $`'&{client_addr} " has been refused. DNSBL list: SpamCop (bl.spamcop.net)."', `t')dnl FEATURE(`dnsbl', `zen.spamhaus.org', `"554 Rejected: Unsolicited e-mail from " $`'&{client_addr} " has been refused. DNSBL list: Spamhaus (zen.spamhaus.org)."', `t')dnl ======================================= Cause --------------------------------------- https://www.spamhaus.org/resource-hub/email-security/service-update-spamhaus-dnsbl-users-who-query-via-cloudflare-dns-need-to-make-changes-to-email-set-up/ https://www.spamhaus.com/resource-center/if-you-query-spamhaus-projects-dnsbls-via-cloudflares-dns-move-to-the-free-data-query-service/ ======================================= Easy Fix /etc/resolv.conf --------------------------------------- Do not use Cloudfair DNS nameservers on your sendmail server. 1.1.1.1 cloudfair 1.0.0.1 cloudfair Just use any other DNS nameserver or set up your own bind server. 9.9.9.9 quad9 149.112.112.112 quad9 208.67.222.222 opendns 208.67.220.220 opendns 84.200.68.80 dnswatch 84.200.70.40 dnswatch 94.140.14.14 adguard 94.140.15.15 adguard 185.228.168.9 cleanbrowsing 185.228.169.9 cleanbrowsing 76.76.2.0 controld 76.76.10.0 controld 8.8.8.8 google 8.8.4.4 google =======================================