T&T: T&T List Admin: "Bounced" email from the list - AN EMAIL FROM THE LIST ADMINISTRATOR

[Bob McLeran (T&T List Administrator)]

AN EMAIL FROM THE T&T LIST ADMINISTRATOR

Several subscribers have posted to the list in the past two days, either
questioning whether the list was working, or indicating that they were
notified that list email to them "bounced."

Please be assured that the list is working just fine; the few who are
experiencing problems are most likely having problems with their
Internet Service Provider's (ISP) e-mail server. This type of problem
comes up with some users periodically; the problem lies with the user's 
ISP, most frequently an overloaded mail box.

Here's a two-part explanation of what it means when an email "bounces,"
First,  a quick and dirty explanation, and appended on the end, a more
detailed explanation for those who can never have enough information!

                 THE QUICK & DIRTY EXPLANATION.

When the software that operates the T&T List (and all of the lists owned
by Georgs) receives a post from a subscriber, it turns around and sends
a copy of that email to every subscriber. Those getting the digest
version get those emails bundled into one long email sent once a day,
around midnight, eastern time.

When an email sent by the list cannot be delivered for any reason by the 
ISP to the intended recipient, the subscriber's ISP automatically sends 
an email back to the list server saying "Huston, we've got a problem" or 
words to that effect. That is a BOUNCE.

The list software keeps track of the bounces by specific subscribed
address, and if it continues over a period of time the subscribers
account is disabled; in other words, the list software stops sending
list email to that account - the account is disabled (not unsubscribed).
At the same time, the subscriber is notified by an email automatically
generated by the list software, with an explanation about how to
re-enable his/her account. All the subscriber has to do is follow the
instructions, and the account is re-enabled. However, it won't do any
good if the problem that caused the bounce in the first place still
persists - email from the list will continue to bounce, and eventually
the account will be disabled again.

The most common reason email to a subscriber bounces is that the user's
(subscriber's) inbox is full and the ISP cannot accept any more email -
more or less like the mailman pulling up to your mailbox (we still have
mail boxes here in Merritt Island, Florida) only to find that it is
stuffed full and there's no room for the letters that need to be
delivered. There are other, more technical reasons, but essentially the
problem is related to something being wrong at your ISP or inbox.

Very few subscribers ever have a problem. In the past two days nine
subscribers (out of almost 2,000 total subscribers) did have email
"bounce" and their accounts disabled. I get notified when an account is
disabled, but have no way of knowing why.

Bottom line: if you suddenly stop receiving list email, check your inbox
using a web browser to make sure old email is being deleted. If it's
full, delete all you possibly can; if it's not full, contact your ISP
and explain what happened. Your email client (program) should be set to
automatically delete old email at certain intervals; if you don't know
how to do that, check the help files available for your particular email
client (please don't ask on the list).

If you have any questions, please email me directly.

Keep on trawlering!

Bob McLeran
T&T List Administrator

                THE MORE DETAILED EXPLANATION

This info may assist if you're going to discuss the matter with your
ISP. Generally the cause of a bounce is a full inbox, but there could be
other reasons an email from the list (or other senders) is undeliverable.

Any mail that is undeliverable, for any reason, counts as a "bounce" ff
the ISP returns it to the list as undeliverable. An email that is
temporarily undeliverable increments the score by 0.5; an email that is
permanently undeliverable increments the score by 1.0. No matter how
many emails bounce during a day, the score will increment only by 0.5 or
1.0 - it is not incremented for every bounced email during the day's
period. If no bounces occur for three days, the score is dropped to
zero. When the score reaches 4.0, the account is disabled (not
unsubscribed); once the account problem is fixed (usually because
of a full inbox), the subscriber can go back into their account and
remove the check from "nomail" and the account should become active
again (if that doesn't work, just let me know and I'll fix it).

Here's the "official" explanation from Mailman, the software that
operates the T&T List.

These policies control the automatic bounce processing system in
Mailman. Here's an overview of how it works.

When a bounce is received, Mailman tries to extract two pieces of
information from the message: the address of the member the message was
intended for, and the severity of the problem causing the bounce. The
severity can be either hard or soft meaning either a fatal error
occurred, or a transient error occurred. When in doubt, a hard severity
is used.

If no member address can be extracted from the bounce, then the bounce
is usually discarded. Otherwise, each member is assigned a bounce score
and every time we encounter a bounce from this member the list server
increments the score. Hard bounces increment by 1 while soft bounces
increment by 0.5. The server only increment the bounce score once per
day, so even if the server receive ten hard bounces from a member per
day, their score will increase by only 1 for that day.

When a member's bounce score is greater than the bounce score threshold,
the subscription is disabled. Once disabled, the member will not receive
any postings from the list until their membership is explicitly
re-enabled (either by the list administrator or the user). However, they
will receive occasional reminders that their membership has been
disabled, and these reminders will include information about how to
re-enable their membership.