Webmail vs IMAP4 vs POP3. Or not?

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
  1. User with multiple email clients
  2. 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.

  3. Multiple users sharing a mailbox
  4. 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.

  5. Multiple users sharing a mailbox and using multiple email clients
  6. 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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