[Boatanchors] E-mail delivery timing issues (was: Re: Electric Radio Issues)

[Mike A]

On Fri, Apr 24, 2015 at 02:02:47PM +0000, Don Merz via Boatanchors wrote:

> Free email is neither secure nor guaranteed. If you want those qualities
> in your email, such service is readily avaialable for a fee from the same
> suppliers you would expect--like Google.

(not entirely boatanchorish, but related to delivery of list E-mails)

Even paid-for E-mail is (in general) not guaranteed. E-mail protocols are
constructed in accordance with RFC 821 and 822 and their (numerous) successors.
The best you'll get from it is "best effort", but any intermediate host in the
chain of mailhosts may lose (or intentionally drop) one or more messages without
notice to the sender or to any of the recipients. That's just the way it works.

Moreover, if a mailer task fails unnoticed, then outbound mail managed by that
task may not be delivered until the task has been restarted and has been told
to re-run the outbound queue(s). I have seen this more times than I care to
remember. The outbound mailer's choice of the next mail(s) to be delivered can
be idiosyncratic, based on its' notion of the speed of delivery of the
previous message to the same (set of) destination mailer(s), the size of the
mail, the priority/precedence given to the mail by the sender's mail client,
the phase of Luna, the barometric pressure and pressure tendency, and other
criteria even less evident.

Webmail, where it is entirely internal to a given provider[1], may or may not
provide guaranteed delivery. But webmail inside, say, AOL, isn't necessarily an
RFC 821/822-and-later protocol, which is what I think we're talking about.

I've been doing E-mail (and computer security and nameservers and stuff) for a
living for Almost Long Enough. Retirement comes after the first payday in March
2016.

[1] E.g., AOL, Gmail, Yahoo!

-- 
Mike Andrews, W5EGO
mikea at mikea.ath.cx
Tired old sysadmin