DiPot: Ice Tea tech » Standards

Webmail vs IMAP4 vs POP3. Or not?

ageor — Tue, 16 Nov 2010 22:14:24 +0000

With email dominating a good part of our communication, mailbox management is an ever growing issue. This is primarily intended for people who access their email from at least two different email clients (webmail counts as one) and people who share a mailbox with others.

I want access to my email via webmail and offline acceess on my two laptops and mobile phone. Worse than that, I am using 2 different email clients on each laptop (one I regularly use and one I am trying). So, I frequently get to answer the question “How to best setup my client(s) to receive email; POP3 or IMAP4?” for myself and others. As usual, there is no single answer. However, there may be a proper email setup strategy for some scenarios. Good understanding of the tools will, hopefully, help determine which one it is. First, some background:

Webmail

Webmail is actually a web-based email client. As such, it is accessible from a web browser and it talks directly to the email server instead of transferring emails locally.

Webmail can be a one stop shop, provided there is access to the email server, which probably also requires Internet access. Yahoo! mail, Hotmail, Gmail, the upcoming Facebook Social Inbox etc. are full fledged email clients that can receive, send and manage emails, complete with antispam, folders and address books. A webmail user has no need to know about protocols to enjoy complete use of an email system, unless he would also like to access email offline. In that case, use of an email client like Pegasus, Eudora, Outlook Express, Outlook (yes, they are different), Evolution, Thunderbird etc. (forgive me if I missed your mailer of choice) is required.

SMTP (Simple Mail Transport Protocol)

Not to be forgotten, SMTP is the protocol that sends email. It is used by all email clients in both POP3 and IMAP4 configurations.

POP3 (Post Office Protocol v3)

POP3 ia a protocol for one way transfer (reception, downloading) of email from the server to the client for offline use. It is supported by all of the above (and more) mailers.

Once an email is succesfully received by the email client, it is, typically, erased from the mailbox at the server. Thankfully, most mailers allow the user to modify this behaviour so the mailer leaves the email at the server’s mailbox as well, either indefinitely or for a preset amount of days. Not erasing an email from the server is so important that Gmail (basically a webmail system) supports setting emails to not be erased on the server side, in case email clients are setup wrong.

So, when we need to have our mail delivered to more than one clients, we can set them up so they don’t erase downloaded emails from the server. This way, email stays on the server ready to be downloaded again or to be accessed via a webmail client.

IMAP4 (Internet Message Access Protocol v4)

IMAP is also supported by all of the above (and more) mailers. It is usually perceived as another protocol to receive email. Well, it is not! It ia actually a protocol to synchronize folders on the email server with folders on the email client(s). Email reception is, effectively, a subset of that.

So, what exacly is the difference and why is it important? Here is a partial list (visit a more comprehensive list and “Internet Message Access Protocol” in Wikipedia). The reason I use “differences” over “advantages” is that advantages depend on the usage scenario:

	Some IMAP and POP protocols differences		Best protocol for scenario
	IMAP	POP	User with multiple email clients	Multiple users sharing a mailbox
Mailbox Size	The complete mailbox resides on the server and requires the corresponding disk space. Depending on how email is synchronized in the clients, they may require less disk space than on the server	At worst, only the size of the “Inbox” folder, provided that mail is not deleted when received (default behaviour)	POP	POP
Folders Structure	The structure of the email folders is the same in the server and the clients and any change propagates from the server to all the clients. If you like to arrange your emails in folders, you only have to do it once for all your clients and the server. Only folders subscribed-to are synchronized	The structurs must be maintained on every client separately	IMAP	IMAP
Direction	Emails get copied both ways; from the server to the client(s) and from the client(s) to the server. This applies to all folders (including “Sent Items” and “Drafts”). It also applies to any number of clients	Email transfer goes only from the “Inbox” folder on the server to the client(s)	IMAP	IMAP
Email Status Synchronization	Email status of “Deleted”, “Read” and “Starred” synchronizes as well. When it changes, it first propagates to the server and from there to all clients	Some clients can direct the server to delete emails that are deleted locally. “Read” and “Starred” status is local to the clients and to the server and does not synchronize in any direction	IMAP	POP
Deletion	Email deletions move both ways. Once a deletion happens on or reaches the server, it propagates to all the clients	Clients never ask for the same email again. Once downloaded, nothing will happen to it in the client, even if deleted on the server	IMAP	POP
Push email delivery	Yes, when both server and client support the IDLE command	No	IMAP	IMAP

User with multiple email clients

IMAP is clearly better for a single user with multiple clients, provided there is enough room for the mailbox on the server. Even with a limited mailbox, a backup of older emails will allow deletion from the server. This backup can be available in as many of the clients as needed.

Multiple users sharing a mailbox

Complete synchronization, a clear advantage for a single user, turns into a disadvantage when multiple users share an email account. I wouldn’t want my collegue(s) to erase the emails he doesn’t like for me as well. I have my own important emails to star. I don’t want to have emails I haven’t read yet appear to be read because someone else read them. And I have my own way to organize my inbox. I want my own email statuses and organization. But I also need to have access to the emails he composes and sends through this account. This is the one synchonization I need.

Thankfully, a mixed IMAP and POP system can be configured to optimize for all needs. The solution I suggest to this (quite frequent, I may add) problem is: Set it up twice. Once as POP3 without deletion for email reception and once as IMAP for the “Sent Items” (or “Sent”) and “Drafts” folders synchronization. Care is needed to not send email from the POP edition of the account. Even then, if the sent email is manually or automatically -via a rule- moved to the IMAP “Sent” folder, the result will be the same. Please note that while sent items and drafts will synchrnize back to the server, any folder-based organization of the email won’t happen on the server, therefore it won’t appear during mailbox access via webmail.

Multiple users sharing a mailbox and using multiple email clients

Unfortunately, the second scenario doesn’t mix well with the first. If I want to organize my shared mailbox in folders and access it from multiple clients, I will have to do so manually on each client. This is a scenario where incoming mail needs to arrive to a mailbox all my own. Actually, nothing a good old mail forwarding setup can’t do, at the expense of multiple times the incoming email space on the server…

How many devices and email clients do you use? Are you happy with your setup? Please share!

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Microsoft IE and Standards Compliance

ageor — Sat, 29 Dec 2007 08:17:12 +0000

There is an indirect update to my December 16, 2007 “Web browser standards: Opera Software vs Microsoft” post in the “Internet Explorer 8 and Acid2: A Milestone” IEBlog post. The way I see it, Microsoft effectively confirms allegations about not complying with standards (by, at least, not seriously updating IE6 in over 5 years and creating lots of problems with IE7) promising it will do so with IE8:

“… IE8 now renders the “Acid2 Face” correctly in IE8 standards mode. …”

“… With respect to standards and interoperability, our goal in developing Internet Explorer 8 is to support the right set of standards with excellent implementations and do so without breaking the existing web. This second goal refers to the lessons we learned during IE 7. IE7’s CSS improvements made IE more compliant with some standards and less compatible with some sites on the web as they were coded. Many sites and developers have done special work to work well with IE6, mostly as a result of the evolution of the web and standards since 2001 and the level of support in the various versions of IE that pre-date many standards. We have a responsibility to respect the work that sites have already done to work with IE. We must deliver improved standards support and backwards compatibility so that IE8 (1) continues to work with the billions of pages on the web today that already work in IE6 and IE7 and (2) makes the development of the next billion pages, in an interoperable way, much easier. …”

If you wonder who made the “existing web” prone to “breaking”, I don’t. In my mind, it was Microsoft. When IE was dominant, it never completely adhered to standards, while extending HTML in all sorts of ways. When standards emerged or caught up, was IE updated accordingly? No.

Is Microsoft finally entering a standards compliance era? How, by adding a “Standards mode” in IE8? I still have my doubts and for good reason. You see, past experience says otherwise.

Web developers, Microsoft hasn’t and won’t ever do it for you. If you are interested in every computer owner being able to fully utilize your sites, please do us all a favor and comply to universal, not Microsoft standards. Windows percentage in the PC market is still very large but dropping. Make them build a decent browser; or not, who cares? Firefox, Opera etc. are excellent, compliant and multiplatform browsers. Don’t build the Internet depended on ActiveX and anything else non-standard enough so only IE (therefore only Windows) users can view.

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Web browser standards: Opera Software vs Microsoft

ageor — Sun, 16 Dec 2007 15:45:08 +0000

Don’t you just hate it when a web page won’t show correctly in Firefox or any non-Internet Explorer browser?

I have always wondered why any web developer would block all Linux & Mac OS users out of their sites and frustrate a good portion of Windows users, those who prefer Firefox. On top of that, some sites don’t even look the same in IE6 & IE7 due to incompatibilities of their own, which recently forced Microsoft to decide to make IE7 available to illegal Windows owners as well!

Over time, it is a well-known fact that Microsoft won’t respect standards very much. Java has been a good example and HTML compliance is no different. So, what’s new about any of that? This extract from the Friday, December 14, 2007 8:00 AM PST Paul Meller and James Niccolai’s PC World article “Opera Seeks Tougher Remedy in Microsoft Case“, describing the “… antitrust suit filed with the Commission this week …” by browser maker Opera Software, which I find especially interesting and long overdue:

“… In addition to the bundling charge, Opera also complains that Microsoft does not follow Web standards, putting rival browsers at a disadvantage. The issue is significant because if all Web browsers do not use the same standards, Web site developers are likely to design their Web sites to work with the most widely used browser, which is Internet Explorer. That gives people a disincentive to use other browsers.

Microsoft often takes part in debates over Web standards, and says it will implement them, but ultimately does not, Opera’s Lie said. He pointed to CSS, XHTML and DOM as areas where Microsoft does not comply with or is inconsistent. …”

I will follow up on this with great interest. I would prefer users and the industry to force Microsoft (and web developers) to comply by (prefferably open) standards (the cornerstone of the Internet), but a court might as well do it…