Sam Tuke via mailop wrote: > With Gmail's self filtering folders, for many smaller hosts the > chances of a message which gets a 250 response code being "received" > (reach the eyeballs of the intended recipient) is lower than not. So > 250 says more about Gmail internals (e.g. the message wasn't > rejected by the first gatekeeper) than it does about successful > delivery. End users still complain that messages weren't delivered, > and we have to investigate each time.
The 250 code you refer to is the SMTP handshake and says only that the mail was transferred successfully between two mail relays. It's no different than sending an ACK after receiving a FIN in a TCP connection. It's a transmission protocol state transition indication. The SMTP response only applies to MTAs, mail transfer agents. It does not apply to MUAs, mail user agents. There is no ability and has never been an ability anywhere at any time to know that someone has read the message. Plus the SMTP protocol has never tried to be an end user visible protocol. Which, if implemented over Avian Carriers, might be unappealing to the consumer. Even if the cost is only bird seed. The diagrams in RFC 2549 I find the most enjoyable. Bob _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
