Martin A. Brooks wrote: > On Tue, June 1, 2010 06:08, W B Hacker wrote: >>> 2. Once the mail has gotten into their system, whether that is delayed >>> or >>> not, it can take up to 2 hours or so for it to show up in mailboxes. >>> >> Now THAT is a scandal.... > > Not really, SMTP makes no guarantee about how long message delivery will > take. If you're relying on your messages reaching the destination inside > a given time window, then SMTP is the wrong protocol to use. > > > > >
Welll. International Private Leased networks, as at the time I retired in 1994, were held to a downtime of around two seconds a year. In theory, neither terrestrial voice telephony nor smtp are even close to a match for those data circuits - let alone GSM and friends. In practice, however, smtp punches well above its weight 'often enough' - just as voice telephony does - as to sustain a user-community *expectation* of near-instantaneous delivery, and near-as-dammit all the time. It is that statistically-supported and experience-driven expectation we have to deliver to. RFC's tell us how. But not always 'how well'. I'd bet the user community waiting out those two-hour transfers includes an ever-increasing number who have acquired Gmail, MSN/Hotmail, Yahoo et al accounts - first for 'emergency' workarounds, later for more and more traffic just on the convenience factor. Eventually, the involvement of the 'official provider' migrates from precarious to historical. End-users are merciless. And they care less about disclaimers than fish do about bicycles. YMMV Bill -- ## List details at http://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
