POPmail

There are a few different permutations to using POPmail that you may want to consider when planning on how to implement a POP solution for your remote messaging needs. For the purposes of this document, let's assume you have a computer at work called "work.whoi.edu" and a computer at home called "home.whoi.edu" that was setup through the WHOI PPP system and both machines already work on WHOInet correctly (Yes, I know this is a big assumption, But work with me on this).

The Delete-And-Run Approach:

     In the DAR approach, you configure work.whoi.edu to delete all POPmail from the server after downloading. You also configure home.whoi.edu to do the same. The end result is that any message you read on either of your machines is transferred to that machine and is only accessible from that machine. In other words, if you get a message from emcmahon@pub-clearinghouse.com during your working day and you read it on work.whoi.edu, then that night when you go home and want to double check your winning numbers, you're out of luck, the message is now physically sitting on work.whoi.edu and is only accessible from that machine.

     Similarly, if you get a message regarding some important data results and you read this on home.whoi.edu, the next day when you need that data for immediate publication, well, it's time to consider an alternative career path.

     The Pro's to the DAR approach: You're being a good network citizen, your email is sitting on the machine where you work, and if you work on a laptop that you carry around with you, that means that all your messages are in one tidy location.

     Con's to DAR: Pretty obvious. Once a message is on one machine, it's not available anywhere else without cleverware like Timbuktu.

The Work-Is-Master Approach:

     In this system, you configure work.whoi.edu to delete mail from the server and keep all messages locally. You also configure home.whoi.edu to leave mail on the server after download. This means that if you get email after you get home, that the message is copied from the server to your home machine, where you can display, reply and so on, but that the next day when you get to work you get to see it again when work.whoi.edu contacts the mail server and downloads and deletes your mail from the POP server. In this sense, your work machine always has a copy of your email messages.

     Pro WIM: A nice way of making sure you can address email issues at home, but that the next day you aren't left floundering for messages that are stuck on a machine turned off at home.

     Con WIM: You end up seeing the same messages twice; that is, any mail that arrives after you leave work will show up at home, and then the next day you'll see it at your work machine again. Slightly annoying.

The Home-Is-Home Approach:

     Basically just reverse the WIM approach. You set your work machine to download copies and you setup your home machine to download and delete. You can work out the pros and cons on your own (I hope).

The Geek-Without-An-Island Approach:

     This is the final permutation.  In this setup, you have both work.whoi.edu and home.whoi.edu setup to only download copies of your electronic mail. Neither machine will actually be removing things from the mail server at any time. GWAI is not generally advised as it can create a plethora of problems described in the Con's section below.

     Pro GWAI: If you're moving around a lot and don't trust the environment you're going to be working in for stability, you always know that at least somewhere on some machine someplace on the planet exists a copy of all the mail that you've received. As we migrate to IMAP mail, this will sort of be how things work (except deletions will be taking place, of course, but directly on the server).

     Con GWAI: Almost too many to list. But the crux of the problem is that every time you connect to a POPserver from a POP client, it will show you all messages that that particular client has not seen before. So if you forget to check your mail from home for 5 or 6 days (and therefore can't call yourself a geek), But are checking it every day at work, then the next time your home machine attempts to connect to the POP server, you'll be presented with 5-6 days worth of email that will need to be downloaded. It can be quite confusing remembering which messages you've dealt with and which you have not.

     The other directly related problem to this approach is that the way in which each client knows to transfer down copies of new messages is to compare its internal list of messages seen vs the number of messages on the server.  However, it can take several seconds to get to the end of the mail spool file on the server and this too can choke Eudora and other POP clients. It's a bit like having to hold your breath whilst running through a smoke filled room. Your destination is the clean air (new messages) at the end of the hall, But the smoke can be overwhelming..and if your POP client can't hold it's breath for the whole run through the smokey darkness of old messages, it chokes, gasps and, well, you get the idea.

So there you have it, the four basic permutations to the POP problem. Why is POP so ugly? Well, keep in mind that it was developed as a way for people to get away from Unix command line interfaces to electronic mail and have a distributed, client based, GUI driven interface to electronic messaging. But it was also designed with the thought that everyone would have a computer on their desk at work and that would be it. Computing at home wasn't really addressed in the context of a logical AND operation.  Instead, POP was considered an exclusive OR service. If you want POP mail at home, you point your single client to a single server on a single Internet Service Provider and that's it..you don't keep mail on their machine, you download and delete every time. Works great for ISP's because they don't have to spend as much in resources. Trouble is, POP breaks down as soon as you want to use the word "and" in describing how you want to work.

IMAP really is the way to go for now, and we are rolling that out as quickly as we can...this document though isn't meant to sell you on IMAP, that should be obvious by now. If you must use POP, then use it with the above configurations in mind!