1. A computer-implemented method, comprising: receiving, at an authorizing Domain Name System (DNS) system, a redirected target domain DNS query from a receiving email system, the redirected target domain DNS query generated by the receiving email system based on parsing Sender Policy Framework (SPF) macro statements in an email domain validation record generated by an email domain owner system and published as a DNS TXT record at the DNS server of the email domain owner system, the redirected target domain DNS query including identifying information of a delivering email system, the identifying information comprising at least one of an extended HELO (EHLO) name and an (Internet Protocol) IP address of the delivering email system; extracting the identifying information from the redirected target domain DNS query; determining an identify of the delivering email system from a list of delivering organizations based on the extracted identifying information by accessing a database that associates at least one of an EHLO name and an IP address with delivering organizations to determine the identity of the delivering email system based on the identifying information; generating, in response to determining that the identified delivering email system is authorized to deliver email on behalf of the email domain owner system, a target validation record, the target validation record including one or more SPF rules indicating that the delivering email system is an authorized sender of email for the email domain owner system; and transmitting the target validation record to the receiving email system.
1. A computer-implemented method, comprising: receiving, at an authorizing Domain Name System (DNS) system, a redirected target domain DNS query from a receiving email system, the redirected target domain DNS query generated by the receiving email system based on parsing Sender Policy Framework (SPF) macro statements in an email domain validation record generated by an email domain owner system and published as a DNS TXT record at the DNS server of the email domain owner system, the redirected target domain DNS query including identifying information of a delivering email system, the identifying information comprising at least one of an extended HELO (EHLO) name and an (Internet Protocol) IP address of the delivering email system; extracting the identifying information from the redirected target domain DNS query; determining an identify of the delivering email system from a list of delivering organizations based on the extracted identifying information by accessing a database that associates at least one of an EHLO name and an IP address with delivering organizations to determine the identity of the delivering email system based on the identifying information; generating, in response to determining that the identified delivering email system is authorized to deliver email on behalf of the email domain owner system, a target validation record, the target validation record including one or more SPF rules indicating that the delivering email system is an authorized sender of email for the email domain owner system; and transmitting the target validation record to the receiving email system. 4. The method of claim 1 , further comprising: determining that the identified delivering email system is in a known list of delivering email systems.