The IMAP advantage

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Has this ever happened to you? You’re on the road or working at home and you need an important e-mail message. The problem is that you downloaded it at the office, and there it sits, inaccessible, on your desktop Mac. If you use standard POP e-mail accounts and more than one Mac, there will probably be times when an e-mail message you need is on the machine you don’t have. There is a solution: IMAP.

Most e-mail programs retrieve and keep track of messages in one of two ways—Post Office Protocol (POP) or Internet Message Access Protocol (IMAP). A POP client stores e-mail messages in mailboxes on your Mac and keeps track of which messages you’ve read, replied to, and so on. At some point, the POP client will delete old messages from the server.

By contrast, if you use an IMAP client and e-mail account, the original messages stay on the server, along with a record of whether you’ve read, replied to, or forwarded a message.

If you’re a mobile user, using IMAP means your inbox looks the same from any computer or any Internet connection. All your incoming, sent, and saved messages are there. You can also switch between e-mail clients, without having to reimport all your messages.

IMAP has its drawbacks. First, your ISP may impose a storage quota, and that space can fill up quickly. (Of course, you can always archive messages on your Mac if you need to.) Second, some e-mail programs (such as Bare Bones Software’s Mailsmith) don’t support IMAP. Third, IMAP can be painfully slow over a dial-up connection—especially with Apple Mail.

Switch from POP to IMAP

The first step in switching from POP to IMAP is to check to see whether your ISP offers IMAP access to your existing account. If it does, find out the name of its IMAP and SMTP servers, the kind of authentication the servers use, and whether Secure Sockets Layer (SSL) is required. You may also need to get a new user name and password. If your ISP doesn’t offer IMAP, you can find a list of providers who do. (.Mac accounts include IMAP access.)

Once you’ve got an IMAP account and all the necessary settings, you’ll want to configure your e-mail client to use it. Setting up IMAP in Mail and Entourage is pretty straightforward. For the basics of setting up a new account, see their respective Help files. In Mail, select Mail: Preferences: Accounts and click on the plus sign (+) button. Choose IMAP from the Account Type drop-down menu, and then fill in the rest of the details (the account description and your user name, e-mail address, and password) as usual.

In Entourage, choose Tools: Accounts to dis-play the Accounts window, click on the New icon, select IMAP from the Account Type pop-up menu, click on OK, and then fill in the rest. If your ISP requires SSL for IMAP, select the Click Here For Advanced Receiving Options button and then select This IMAP Service Requires A Secure Connection (SSL).

Move your messages

After you’ve set up your IMAP account and configured your e-mail client to use it, you can move messages from your POP account (stored locally on your Mac) to the IMAP server.

In Mail, you can simply drag one or more mail-boxes from your mailbox list onto the icon representing your IMAP server. Mail copies the mailboxes (even nested ones) and their contents to the server, creating new mailboxes as needed.

In Entourage, you must first create a new IMAP mailbox. Select your IMAP account in the Folders list and click on the arrow to the right of the New button and then scroll down to select Folder. Type in a name and click on Create. Once that’s done, select all the messages in your local mailbox and drag them to the new IMAP mailbox on the server. Repeat for each of your mailboxes. When you’re done, you can delete your local mailboxes.

IMAP tips

Now that you’ve got your IMAP account established, it’s time to start learning a few good IMAP habits.

Keep Your Inbox Trim Whether you use rules (or filters) to redirect incoming messages into other mailboxes or sort your messages manually, try to limit the number of messages you store in your inbox; a good target is 40 or fewer. An overloaded inbox can slow down your e-mail client (especially if you use Mail) and make it harder to find messages.

One way to keep your inbox clean is to get into the habit of moving messages into subject-specific mailboxes as soon as you’re finished with them. Doing this will also speed up searches.

In addition, you should go through old messages every month or two and delete (or archive) any messages you no longer need to access from other clients or computers.

Watch Out for Special Folders IMAP enables you to store Junk, Drafts, Sent, and Trash mailboxes on the server if you wish. Although online storage can be very handy, it can also make syncing your e-mail client with the server much slower and quickly soak up your storage quota. So think carefully about whether you need to store these mailboxes online. If you do, use them sparingly and empty them frequently.

If you don’t want to store these mailboxes online, you can set up your e-mail client to store them locally. To set this up in Mail, go to Mail: Preferences, select Accounts, and then select the Mailbox Behaviors tab. Deselect any mailbox (Drafts, Sent, Junk, or Trash) you don’t want to store on the server—Mail will now store them locally. For mailboxes you want to keep on the server, you can tell Mail when to purge old messages from them (when you quit Mail; when messages are a day, a week, or a month old; or never).

In Entourage, go to Tools: Accounts. Select your IMAP account and then the Advanced tab. Deselect the mailboxes you want to store locally.

Cache Everything Even though IMAP accounts keep your messages on the server, you can cache copies of those messages on your local machine for offline access.

To make sure Mail stores complete, local copies of all your messages, select Preferences: Advanced. Then, under the Keep Copies Of Messages For Offline Viewing pop-up menu, choose All Messages And Their Attachments (see screenshot).

In Entourage, select Tools: Accounts, double-click on your IMAP account, and then select the Options tab. In the Server Options section, select Always Download Complete Message Bodies and deselect Partially Receive Messages Over Number KB.

Stay in Sync One tricky thing about using IMAP from multiple Macs is making sure the messages you store locally on your various machines all match the copies stored on the server.

Ordinarily, Mail will synchronize server mailboxes with your e-mail client only periodically. To change that, you could select Automatically Synchronize Changed Mailboxes in the Advanced tab of your IMAP account. Unfortunately, doing this can slow down Mail and overtax a slow network connection. Instead, synchronize messages manually (especially before going offline) by choosing Mailbox: Synchronize: Account Name (or Mailbox: Synchronize All Accounts).

By default, Entourage synchronizes only the contents of your inbox with the server; it synchronizes other mailboxes when you open them. To synchronize more mailboxes when Entourage checks your IMAP account, choose Tools: Schedules and double-click on the schedule that includes your IMAP account (such as Send And Receive All). Then click on the Click Here For Account Options button next to your IMAP account in the list. Select each mailbox you want to synchronize automatically. Even if you choose Headers Only for a given mailbox, Entourage will download full messages if you chose Always Download Complete Message Bodies in the previous step.

Once you’ve got IMAP set up on your laptop, you can travel the world knowing that all those messages are sitting safely on the server, accessible from any Mac, at any time you want.

[ Joe Kissell is a senior editor for TidBits and the author of the e-book Take Control of Apple Mail in Tiger. ]

Cache In: Using this pop-up menu, you can choose whether Mail caches all, some, or none of your e-mail messages locally (in addition to keeping copies on the server).
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