Date: Mon, 16 Dec 1996 11:31:56 EST From: rototink Subject: FILLER: Where The Mail Might Be... [since I have seen some evidence of concern about delivery and order and so forth, let's talk techy for a little. pray pardon my nerdiness, but I think this might help...] let's imagine, for a little while, that we have some fairly trustworthy but stupid clerks (aka computers). Suppose that when you wrote a letter, you handed it to one of these clerks. He immediately scribbled down a copy (very accurately because he doesn't have much imagination) and then said "GOT IT!" to let you know he was on the job. He then calls up his friend (another computer) on the phone. The line could be busy, his friend could be sleeping, all kinds of problems. But he is persistent, trying again and again. In some cases, he'll even get inventive and start trying friends in other locations to see if maybe they can go around the problem. When he gets through, his friend scribbles down a copy, and then says "GOT IT" to let him know that the message is one step closer to being delivered. Your local clerk then erases his copy, knowing that his buddy is just as persistent about delivering the mail. There may be several steps like this, with each clerk keeping a copy until the next one assures him that they "GOT IT". Eventually, in the case of mail to the list, it gets to LISTSERV@mitvma.mit.edu. He is a special kind of clerk - he's got a copier! He takes every piece of mail that he is handed, makes a stack of copies for each of the people on that particular list, and starts sending out individual messages to everyone. The mail from listserv wanders back out through the same kind of series of clerkly handoffs, each one telling the last one that he "GOT IT" until, in the fullness of time, a copy is delivered to you. Just as an example, when wlantry@owl.engl.sru.edu sends mail, it goes through unclebill.sru.edu to rock2.sru.edu and into mitvma.mit.edu. At any of those steps, the mail can sit. Ordinarily, when network connectivity and telephone lines are in good shape, it goes through very quickly. But...it can sit. And sit. And sit some more. I fairly often get little advisory messages saying that a message hasn't been delivered within four hours, and the site will continue trying for seven days. [last Wednesday at MIT was a rather exceptional day because the entire email system decided to go on strike. This provided the students with a great deal of relief on their final day of classes, and amused the rest of us as we watched the network group go nuts...of course, since these are my neighbors and compatriots in griping about work, it was also somewhat stressful listening to people complain. From about 2 am until 5 pm, all mail that went through mit.edu waited. I'm not sure whether any of you out there saw delays, but it was very quiet inside mit...] just think of this little series of clerks, each one copying down and then saying "GOT IT" to the last one. When one stops to sneeze, have a hamburger, or whatever, the mail waits. That's where the mail sits, and why you don't always get instant service, or orderly delivery. does that make sense? tink