Hello, imagine, a mail envolope contains many recipient, The server accepts the first recipients and rejects the last recipients, meaning “Too many recipients in this transaction”.
RFC 821 specifies the reply code 452 as “Insufficient storage”, which RFC 5821 amends, by stating that 452 can mean also too many recipients in this transaction. RFC 3463 defines enhanced status code 4.5.3 stating “Too many recipients”. RFC 5248 attaches the ESC 4.5.3 to reply code 451, stating that changing this binding requires a specification, and there is no such specificaton. The latter means, that 452 4.5.3 is not valid. Postfix and sendmail send “452 4.5.3”, exim sends on this occasion 452 without ESC. How can Haraka be tweaked to retry immediately: • Does openSMTPD interpret 4.5.3 anyhow special? • Does it handle 451 and 452 differently by default? • If a site publishes many MX records pointing to the same IP address, will openSMTPD do a lot of tries (reducing the amount of pending recipients in each iteration) in shortes time? • If a site published one MX records pointing to many different IPv6 addresses, will openSMTPD do a lot of retries to deliver the same message in shortest time? I guess, that a site publishing many MX records pointing to many IP addresses is not an additional option to increase the retry rate. SpamAssassin recomends inserting fake MX records https://cwiki.apache.org/confluence/display/spamassassin/OtherTricks . How do these impact the retry algorithm? Regards Дилян