This draft assumes familiarity with ARPA standard mail formats (RFC 5321/5322). It is intended to be used in conjunction with localized firewall rules to restrict access to proprietary mail servers, especially for systems that require specific restricted IP source addresses or browser-based logins.
Following the principles outlined in NIST SP 800-177 Revision 1 , this specification prioritizes:
Implementation of specialized commands (e.g., DMTP) allowing receivers to categorize and decline messages from unverified senders, similar to draft-duan-smtp-receiver-driven-02 . 4. Configuration Directives
The .txt file should include the following parameters for mail access control:
Known malicious sources to be summarily declined.
Below is a draft technical overview based on the structure of standard IETF mail access drafts like draft-ietf-imap-imap4-06 and draft-ietf-emailcore-as-26 .
Deployment of TXT records in the DNS to mitigate Man-in-the-Middle (MITM) attacks during mail transport.
IP ranges and domains permitted for direct relay.