The Courier IMAP server

IMAP client configuration

Configuring IMAP clients can be tricky for any server. You have to know a little bit about how the IMAP server works. Recommended Courier-IMAP configuration for popular IMAP client software follows.

Pine (version tested: 4.10)

Older versions of Pine may require the IMAP_OBSOLETE_CLIENT flag in the imapd configuration file. This setting disables the CHILDREN IMAP extension, which breaks older versions of Pine. Current version of Pine do not appear to have this problem.

To configure Pine to use Courier-IMAP for the main INBOX, go to Pine's main menu, select S)etup, then C)onfigure. Go down to "inbox-path" setting, set it as follows:


"hostname" is the name of the server that's running Courier-IMAP. Exit and restart Pine.

Folder configuration

Pine can also create and use folders with Courier-IMAP, instead of creating mailbox files in $HOME/mail. Go to Pine's main menu, select S)etup, then choose collectionL)ist.

Choose A)ddcollection. Pick a name for this folder collection. Enter the hostname of the Courier-IMAP server. For "Path", enter INBOX. Do not enter anything for "View". Press ^X to save and exit.

Now, when you select a folder listing from Pine's main menu, instead of a folder list, you will see two "folder collections" in a menu. The first one will be "Mail - Local folders in mail/". Open that folder collection, and you will see your familiar Pine folders (note, you may also see INBOX there, that's a bit misleading because your INBOX really comes from Courier-IMAP, it's just that Pine always sticks INBOX into the first folder collection). The second menu entry will be your Courier-IMAP folders. If you open it, you'll see just one folder - "Trash". This folder is not really used by Pine, so it can be ignored. You can now create your Courier-IMAP folders by pressing A.

Shared folder access

If your Maildir INBOX has been previously linked, by maildirmake, with one or more sharable maildirs, you can access shared folders by repeating the previous procedure, but entering "shared" into the "Path" field, instead of "INBOX" (of course, you'll have to pick another name for this shared folder collection).

Unfortunately, Pine lists *ALL* of your sharable folders by default. There is, apparently, no individual subscribe/unsubscribe mechanism, by which you get to choose which sharable folders you want to be listed.

For the FAQ: In a shared folder, "expunge" does not remove some deleted messages, why?. ANSWER: You can only delete your own messages in a shared folder (owners of sharable maildirs can delete anyone's messages, though). You may be able to mark the message as deleted, but you won't be able to actually remove it.

Also, when you delete your own messages, others will still see them until you expunge.

Creating folders

The names of Courier-IMAP folders may not contain periods or slashes. Periods are used as hierarchy delimiters - Courier-IMAP and Pine can create folders within other folders.

Choose A)dd folder, then enter "Work.Important". Instead of a new folder being created, Pine will display a new entry "Work.". This is a subdirectory of folders. Move the cursor and press Enter, and Pine will open the contents of "Work", which will contain an empty folder "Important". Choose A)dd folder, and create a folder named "Not Important". You now have two folders shown, "Important" and "Not Important". You can go back to the root folder collection by pressing '<'.

When saving messages to folders in Pine, you can manually type in the complete folder name, "Work.Not Important", or press Ctrl-T, then navigate your folder hierarchy.

You can only delete folders after you've deleted all messages from the folder. If you display the folder collection listing, go to the "Work." subdirectory and then delete both Important and Not Important folders, when you return to the root folder collection, the Work. subdirectory will automatically disappear. Subdirectories disappear automatically when all folders in the subdirectory are deleted.

Folders containing both messages and subfolders.

It's possible to have both a folder named "Work", and a subdirectory named "Work." that contains other folders, however Pine doesn't implement it very well. You can go to the folder collections list, then add a folder named "Work", then add a folder named "Work.Slacking Off".

Pine will display one entry: "Work[.]". Pressing the '>' key will display all subfolders in the Work subdirectory, and pressing Enter will open the Work folder.

There will be a minor problem navigating the folder collection when you're saving messages in Pine. When Pine prompts you for a folder to save a message, you can bring up the folder collection list by pressing Ctrl-T, however there is no way to select the Work folder from the menu. The '>' key will not work, and pressing Enter will always display all subfolders in the Work subdirectory. To save the message in the Work folder you will have to type in its name manually.

Removing the local mail folder collection

You may find it cumbersome to have two folder collections in Pine - the default folder collection of mailbox files in $HOME/mail and the Courier-IMAP folder collection.

From Pine's main menu, choose S)etup then collectionL)ist. You can simply delete your local mail folder collections. Pine will now create its usual "postponed-msgs" and "sent-mail" folders in Courier-IMAP, instead of creating mailbox files in $HOME/mail.

Note - you will lose all your messages saved in local mail folders when you do that, so make sure to back up any messages you want by copying them into a Courier-IMAP folder. Also, even if you remove the local mail folder collection, Pine will not remove $HOME/mail, and it will take up space until you manually delete it.

NOTE - if you use SqWebmail, resist the urge to go into Pine setup and rename "postponed-msgs" to "Drafts". SqWebmail will have a problem with Pine creating and deleting the Drafts folder at will.

Netscape Messenger (version tested: 4.7)

Go to Edit|Preferences. Click on Mail & Newsgroups, choose "Mail Servers".

Enter the name of the Courier-IMAP server, for server type choose "IMAP", and make sure to enter your login name.

Click on the "Advanced" tab, and UNCHECK the option "Show only subscribed folders". Make sure that "server supports folders that contain subfolders and messages" is checked.

Under "Personal Namespace", enter "INBOX.", and don't forget the trailing period. Under "Public (shared)", enter "shared.". You may not actually need to do this, if you use a recent version of Messenger (I believe that Messenger 4.5 and later support the NAMESPACE server extension which automatically configures these values).

There are several known bugs in Netscape Messenger's IMAP client. See BUGS for additional information.

For the FAQ: Clicking on "Get new messages" results in an error message "Error in IMAP command received by server", or nothing happens at all when I know there are new messages in a shared folder. ANSWER: this is a known bug in Messenger's IMAP client. Complain to Netscape. You can try reinstalling Courier-IMAP with the --enable-workarounds-for-imap-client-bugs option, to see if it helps.

Microsoft Outlook Express (version tested: 4.72)

Open the "Tools" menu, choose "Accounts". This is done for you automatically the first time you run Outlook Express. If you already use Outlook Express, select this option manually.

Press the "Add" button, select "Mail".

Enter your personal information - name, E-mail address - when prompted.

Choose 'IMAP' server type, of course.

Specify the name of the server that's running Courier-IMAP, in the "Incoming Mail Server" field.

Specify your usual SMTP server for outgoing mail.

On the next screen, enter your Courier-IMAP logon name and password.

Finish the rest of the set up by giving a name to this mail account. Specify your appropriate connection settings.

You will receive the following prompt:

Would you like to download folder list for the IMAP account you've just created?

Click on "NO".

You will be returned to the "Internet Accounts" dialog. If you are not returned to this screen, choose "Accounts" from the "Tools" menu account.

There will be an entry there for the new IMAP server account that you just entered. Click on it, then choose "Properties". Click on "Advanced".

If you don't need to access any shared folders, enter "INBOX" (without the quotes) in the "Root folder path" field, and make sure that "Only show subscribed folders" is NOT checked.

If you need to access shared folders, leave the "Root folder path" field blank. If you don't have a lot of shared folders, then leaving "Only show subscribed folders" also unchecked would probably be easier. Otherwise, after you download your folder list "see below", shared folders will not immediately show up. You will have to right-click on the folder list and select "Subscribe to all folders". Then, after all shared folders are downloaded and shown, you can right-click and select "unsubscribe" in order to remove any folders that you are not interested in.

Save your changes, and go back to the main Outlook Express window. You will see a new entry in the left navigation tab for the new IMAP server you've just entered.

Click on the new entry. You will be asked again whether or not you would like to download the folder list. This time, answer "Yes".

If you did not configure access to shared folders, all your folders on the Courier-IMAP server will be shown as a single hierarchy. If you enabled access to shared folders, there will be two separate folder hierarchies shown: "INBOX" - your private folders, and "shared" - all your shared folders.

When shared folder access is enabled, you can only create or delete folders by making them subfolders of INBOX. That's your private personal folder space. You cannot create any "shared" subfolders, because that has to be configured on the server side, either by you logging into your shell account, or by the system administrator.

Pine is a trademark of the University Of Washington

Netscape Communicator is a trademark of the Netscape Communications Corporation

Outlook Express is a trademark of the Microsoft Corporation