Qmail mail storage mode Courier

UsedQmailWe all know that there is a mail storage mode-Courier. Today we will introduce its features and usage skills.

Traditional IMAP does not support Maildir mail storage format. To provide IMAP protocol for Qmail users, Courier-IMAP must be installed. Courier-IMAP is a server that provides the IMAP protocol to access Maildir. It does not support traditional Mailbox mail storage.

As mentioned earlier, "Maildir" is a new mail storage method proposed by Qmail to solve users' mail storage problems. Each email is saved in a separate file in the user's personal email directory, and is no longer saved in the/var/mail file as in the past. Multiple applications can access the same email directory at the same time, which avoids the locking problem and is especially suitable for NFS storage that lacks the file locking mechanism.

Courier-IMAP Main Features

* Small and efficient;

* Provides multiple user authentication modules and methods;

* Supports Virtual mailboxes;

* You can limit the total number of simultaneous Logins To IMAP and the number of simultaneous logins to the same IP address. This effectively protects the system from Denial-of-service attacks) the attack will not be paralyzed by overloading;

* Shared folder is supported ).

Download and install

The latest version is courier-imap-0.32-tar.gz. Courier-IMAP automatically listens for connection requests from clients. Therefore, you need to comment out the IMAP service line in the/etc/inetd. conf file. The complete installation process is as follows:

$./Configure [options]

$ Make

$ Make check

$ Make install

Run the following command to start the Courier-IMAP service:

$/Usr/lib/courier-imap/

Libexec/imapd. rc start

If Courier-IMAP is installed in/usr/lib/courier-imap, run the following command to stop the Courier-IMAP service:

$/Usr/lib/courier-imap/

Libexec/imapd. rc stop

You can add these two commands to the system startup and shutdown scripts.

Use of Courier-IMAP

Compared with the POP3 protocol, the IMAP protocol can store users' personal emails in different directories on the mail server instead of downloading them to a local hard disk, it is especially applicable to users who do not have a fixed PC or are often on a business trip. As a mail service provider, we should provide both services to meet different needs of users.

Courier-IMAP supports various Standard IMAP client software, such as Netscape Messenger, Pine, Microsoft Outlook Express, and Eudora. You can select your favorite client mail software (unfortunately, currently, the most popular FoxMail does not support the IMAP protocol ). Note that when using virtual domains and virtual users, due to user permission issues, it seems that it is impossible to create a personal directory outside of InBox. Fortunately, this is not a big problem.

After reading this article, we have some knowledge about Courier and hope to help you!