My 1/25/09 Missoulian column
If you’re an e-mail user, you’re probably familiar with using a Web-based e-mail program or a program that’s integrated into your PC or Mac. Both are ways to send and receive e-mail, but both are slightly different under the hood.
There are three basic ways that e-mail “works”: it’s either post office protocol, Internet mail access protocol or Web based. (Or, it can be a combination of several of those). The explanation of these three gets a little complicated, but it’s worth knowing as it might be handy for background in order to better manage your e-mail.
First of all, it helps to understand the basic mechanics of how computers work with e-mail. In the world of e-mail, there are servers, clients and protocols. Servers are the centralized computers that store e-mail, send it around the Internet and, on request, transfer e-mail to a client – which is the PC or Mac that you use.
(The server-client relationship also goes for the rest of the Internet as a whole – for Web pages, for the ways that files are transferred and copied around the Internet, for Internet-based forms of telephony, and on and on.)
Protocols are the standard “languages” that computers talk to each other in. You’re probably familiar with hyper text transfer protocol – it’s the protocol for transferring and viewing Web pages called “http.”
For e-mail, the protocols that work in the client-server relationship are IMAP and POP. Post office protocol, or POP, and POP3 are the latest incarnation of one of the original ways that e-mail was transferred from a server to a client. Like a post office, POP picks up mail and brings it to your computer. IMAP4 – which stands for Internet mail access protocol – is newer and has different capabilities for transferring your e-mail, namely keeping all your mail at the “post office” – the server – and letting you work with it there.
You won’t see POP and IMAP “by themselves” on your PC or Mac. They are used by e-mail programs such as Apple Mail or Microsoft’s Outlook, and you will usually only see POP and IMAP when you dig into your mail program and configure it for your e-mail account.
The basic difference between POP and IMAP protocols is that POP downloads your e-mail from the server to your PC or MAC and keeps it there, while IMAP keeps your e-mail on the server.
If your e-mail program is set up with POP, your computer contacts the server, finds out if there is new e-mail and downloads it. One minute your e-mail is on the server, the next it’s on your computer and not on the server.
(You can find settings in your e-mail program to leave mail on the POP server for a day, week or indefinitely, but the basic idea behind POP is downloading e-mail from the server and storing it on your client computer.)
IMAP is different in that your e-mail is kept on the server all the time, and when you use your computer to receive and read e-mail, you are actually working on the server. Your e-mail client talks to the server and grabs the message “headers” – who it’s from, the subject line and other normally invisible information – and shows that in your e-mail program. Start a new e-mail and your computer talks to the server, rather than in POP, where your new e-mail stays on your computer until you send it.
This is the IMAP advantage over POP and is a reason that IMAP is growing in popularity. It allows several different computers to deal with your e-mail because your e-mail is on the server and not any one of the client computers that you use.
All your e-mail stays on the IMAP server, and you will see identical copies of all your e-mail on all of your client computers. If you delete e-mail with one computer, it’s gone and won’t show up on other computers.
Of course, IMAP has one significant disadvantage. Because your computer is constantly talking to the e-mail server, you really need faster than dial-up speeds to be able to work. This isn’t a big deal if you have broadband, but on a heavily used lower speed DSL line or dial-up, your e-mail can slow to a crawl.
IMAP is handy because all of your e-mail is there, all the time, across many different computers.
POP is handy because it’s quick and uncomplicated. (For sending mail, both POP and IMAP clients use a yet a different protocol called simple mail transfer protocol, or SMTP, but that’s an extra detail that you don’t really need to remember unless you are setting up your own e-mail client on your computer).
Now, Web-based e-mail is different than POP and IMAP. In Web-based, you don’t need a dedicated program to deal with e-mail, because anywhere you can find a Web browser you can deal with e-mail. Your e-mail is always on the server, and if you want a copy on your own computer, you can print it or cut and paste it. Web e-mail mostly uses Web protocols between you and the server of the Web mail company. From there, standard email protocols are used.
Borders can get blurred between Web mail and client mail. Many people use Web mail on home computers – rather than e-mail clients – because it’s quick and easy and for most purposes, it acts the same.
But Web mail can get more complex – and at the same time – more capable. If you use Google (and some other services) for Web-based e-mail, you can also use Google with a POP or IMAP client such as Apple Mail or Outlook. That means you can use a Web browser to read and send e-mail, but also use a client program to send and receive email through Google.
That can be advantageous because Google is free, comes with lots of free server storage and if you’re on the road without your laptop, you can still use the Web to deal with e-mail. But you can also use other programs – such as calendars, address books, etc – along with your e-mail on your computer.
(This discussion on e-mail protocols has mostly has to do with e-mail on full computers; BlackBerrys, iPhones and other kinds of mobile devices may use forms of IMAP and POP or even proprietary protocols that are private to the companies that produce and use them, and you may or may not be able to easily change the way you work with e-mail on such gadgets.)
If you want to change from POP to IMAP and be able to keep the same e-mail inboxes across different computers, be sure your e-mail hosting will support IMAP (the majority will) and keep copies of your local mailboxes so your mail can be uploaded to the IMAP server. If you don’t use anything other than a Web browser for email, that works. There are ways to make using email more efficient, but if you want to keep it simple, that’s a form of efficiency, too.