Designated Mailers Protocol

Differences from Other Proposals

• Lightest load on Domain Name System (DNS) per query
• Queries both network address and domain at once to reduce data returned
• Statistics provided demonstrate less than 4.5% bandwidth increase compared to SMTP alone (section 8, draft-fecyk-dmp)
• DNS caches and reasonably long time-to-live (TTL) values improve this further


• DMP records are queried on every SMTP delivery
• Some argue this hurts DNS more, statistics suggest this does not
• Greater chance for dynamic queries returning postive results, better support for dynamic IP and roving users


• Does not require changes to DNS or DNS servers
• Not all DNS servers handle unknown record types transparently
• Experimental example exists for arbitrary information in DNS (RFC 1464)
• Simple record design eases implementaton for smaller domains
• Very few smaller domains have control over in-addr.arpa or ip6.arpa records, ISPs are "too lazy" to use classless delegation (RFC 2317)


• Protocol event path clearly defined
• Section 5, draft-fecyk-dmp


• Effectiveness clearly demonstrated
• As great as 20% decrease in SMTP volume (24.5% not including DMP overhead)
• Numbers wanted for other proposals to compare (DMP sample data available for accurate comparisons)
• Similar numbers for other proposals would convince me to drop DMP