https://senderprobe.com/tools/mx-lookup monthly 0.9 https://senderprobe.com/tools/a-record-lookup monthly 0.9 https://senderprobe.com/tools/ns-record-lookup monthly 0.9 https://senderprobe.com/tools/spf-record-checker monthly 0.9 https://senderprobe.com/tools/dkim-record-checker monthly 0.9 https://senderprobe.com/tools/dmarc-record-checker monthly 0.9 https://senderprobe.com/tools/blacklist-check monthly 0.9 https://senderprobe.com/tools/reverse-dns-lookup monthly 0.9 https://senderprobe.com/tools/smtp-server-test monthly 0.9 https://senderprobe.com/tools/txt-record-lookup monthly 0.9 https://senderprobe.com/tools/whois-lookup monthly 0.9