Helping people with computers... one answer at a time.
Email programs, email access and email servers are all frequently confusing to many people. We'll review where email goes, and how you can get at it.
Is there an advantage using Windows Outlook Express email service over an ISP such as Comcast? What is the difference?
The question shows a very common point of confusion.
In a way, it's kind of like asking "which is a faster way to get home, taking Main Street, or driving a Ford?" The two things being compared kind of relate, but in fact are two very different things that don't compare to each other at all. In reality you might take your Ford down Main Street, or perhaps your Maserati traveling on Elm St. would be faster.
Let's sort out this whole ISP, Email Program mess.
Regardless of what service you use for your email, messages sent to you are collected on a server, waiting there until you choose to access them.
Accessing your email falls into two broad categories:
POP3/IMAP: POP3 and IMAP are protocols designed to let email programs running on your PC download or view your email on your PC. Examples of such programs are Outlook Express (on XP or earlier), Windows Mail (on Vista), Outlook, Thunderbird, Eudora, and perhaps hundreds more. The key here is that it's a separate program for email management that runs on your computer.
Web: If you are using web access, you do not run a special program, all you do is point your web browser to a specific URL to reach your email service provider, where you can then access your email. Examples include the default interfaces for GMail, Hotmail, Yahoo mail and the like. The key here is that the mail is accessed through your browser but remains stored on the web; it is not downloaded in the same sense that a POP3 client would download to your PC.
Most ISPs provide email services with the intent that you use a POP3 email client to download your email to your PC. Which email client you use is up to you. So in the case of the person asking the question, you're quite welcome to use Outlook Express, Thunderbird or any of the many other email programs available. It's not an either/or situation, as they're two different things: you might use Outlook Express to access your Comcast email.
Now, here's where things get a little confusing: many ISPs also provide web access to your email, and many web mail services provide POP3 access to your email.
But not all do.
But for those that do, it's simply an alternate way of accessing your email. It can be convenient, or it can be critically important, depending on how you choose to manage your email.
There's an important difference between POP3, IMAP and web access that many people overlook:
POP3 downloads your email to your PC, removing it from the mail server. EMail can be read whether or not you are connected to the internet.
IMAP downloads portions of your email to your PC, but accesses and leaves the messages on your server. You typically must be connected to read email.
Web access does not download your email, leaving it on the server at all times.
So if you've downloaded your email via POP3, it will not be available to your web access. (Caveat: even here things can get confusing, since a POP3 client can typically be instructed to "leave messages on server", but that's not a default or common configuration.)
Another important side effect of this "download or leave on server" distinction is disk space. If you download your email you are limited only by your own available disk space. If you leave email on your server, then depending on the restrictions in place on that server, you can fill up your mailbox and run into other limitations that might cause email sent to you to start bouncing or just not arrive.
And of course anything you do download you have full control over. For example, you can back it up so that you never lose it. Mail stored on a server, once lost, is often lost forever.
I think most major ISPs actually include some form of web access to your email, so I won't try and call any out specifically. As I said, traditionally email is accessed from your ISP using a POP3 email program, but web access can provide an alternate way to get at email that hasn't already been downloaded when you're not at your computer, or if you prefer, as your sole means of accessing your ISP's email. It's up to you.
Web-based email services are a little dicier.
GMail provides POP3 and IMAP access, which is great - you can choose to access your GMail via the web, via the email program of your choice, or some combination thereof.
Hotmail does not support POP3 or IMAP. However, the mail program Windows Live Mail can access Hotmail, and Outlook can access Hotmail with the "Hotmail Connector". Unofficial solutions for other email programs exist; for example, there's a Hotmail add-in for Thunderbird that seems to work quite well. But again, I have to stress Hotmail itself does not provide POP3 access - any solutions that do so are unofficial and unsupported by Hotmail. Hotmail is intended to be web only, unless you use one of the Microsoft mail programs that have been modified to support it.
Yahoo mail is even more interesting. As I understand it, last I checked POP3 access is available only in certain countries, and the U.S. isn't one of them.
As you can see, web based mail services are really intended to be accessed via the web. The ability to use a PC-based email program is often an after-thought, and support varies from very good to none at all.
So the bottom line looks like this:
Email sent to you is collected on a mail server, provided by your ISP or whatever other mail service you choose to use.
PC-based email programs like Outlook Express are most commonly used to download your email from the mail server to your PC where you can read, archive and backup your email, offline or on.
Web-based email access provides direct access to the email stored on your server without needing to download.
Most ISPs intend that you use a PC based mail program to download your email, but may also provide a web-based interface to access email that has not yet been downloaded.
Most web-based mail services like GMail, Hotmail and the like intend that you use their web based interface to access your email stored on their servers. The ability to download email to a PC based program may, or may not, be available.
And for the record: my recommendation is to use a PC based program, no matter what service you use. The reason is simple: I hear too often of lost email that was stored only on an email service's server. If you download - even if only to copy as a backup - you control what happens to that email. You can back it up or do whatever you feel is appropriate to make sure it never gets lost.