Andrew Hudson - Fedora™ Unleashed, 2008 edition

Perhaps you do not want to read your mail in an MUA. If you use your web browser often, it might make sense to read and send your mail via a web interface, such as the one used by Hotmail or Yahoo! Mail. Fedora provides Squirrelmail for just that purpose. Squirrelmail is written in the PHP 4 language and supports IMAP and SMTP, with all pages rendering in HTML 4.0 without using Java. It supports MIME attachments, as well as an address book and folders for segregating email.

You must configure your web server to work with PHP 4. Detailed installation instructions can be found in /usr/share/doc/squirrelmail/INSTALL. After it is configured, point your web browser to http://www.yourdomain.com/squirellmail/ to read and send email.

Although the currently held belief is that Linux is immune to email viruses targeted at Microsoft Outlook users, it certainly makes no sense for UNIX mail servers to permit infected email to be sent through them. Although Fedora does not provide a virus scanner, one of the more popular of many such scanners is MailScanner, available from http://www.sng.ecs.soton.ac.uk/mailscanner/; a Fedora RPM package is available as well as the source code. It supports Sendmail and Exim, but not Postfix or Qmail. Searching on the terms "virus" and "email" at Freshmeat.net will turn up a surprising list of GPLed virus scanners that might serve your needs.

If you already use Hotmail or another web-based email account, the currently available MUAs are not useful to you: Formal POP3 access to a Hotmail account is not available free of charge. However, Microsoft Outlook Express can access Hotmail at no charge, using a special protocol called HTTPMail . How that is done is covered in RFC 2518 as "WebDAV extensions to HTTP/1.1." No specific solution is provided by Fedora, but the basic tools it provides are adequate when supplemented by some clever Perl programming.

Hotwayd is available from http://sourceforge.net/projects/hotwayd/ and implements this functionality, allowing you to use your favorite mail client to read mail from Hotmail.

A newer Hotmail access tool is Gotmail from http://sourceforge.net/projects/gotmail. It is a Perl script that is easy to configure. There are brief tutorials on configuring it for use with KMail and Evolution at http://www.madpenguin.org/cms/?m=show&id=437.

A similar tool exists for Yahoo! Mail. FetchYahoo is available from http://fetchyahoo.twizzler.org/.

After it is implemented, you can use a regular MUA, or mail client, to access your web- based mail. None of them, however, enable you to send mail through Hotmail or Yahoo! Mail.

Fedora provides an imappackage that installs IMAP and POP daemons (servers) for your system. These servers facilitate receiving mail from a remote site. After it is installed, the documentation is found in /usr/share/doc/imapand the Read Me is brief; Fedora has already done the configuration for you; you need only start the services (see Chapter 15, "Remote Access with SSH").

Biff and its KDE cousin KOrn are small daemons that monitor your mail folder and notify you when a message has been placed there. It is common to include biff yin the .loginor .profilefiles to automatically start it upon user login if you want to use Biff. You can start KOrn by adding the applet to the KDE taskbar.

Autoresponders automatically generate replies to received messages; they are commonly used to notify others that the recipient is out of the office. Mercifully, Fedora does not include one, but you can find and install an autoresponder at Freshmeat.net. If you subscribe to a mailing list, be aware that automatic responses from your account can be very annoying to others on the list. Please unsubscribe from mail lists before you leave the office with your autoresponder activated.

One of the last areas in which a Microsoft product has yet to be usurped by open source software is a replacement for MS Exchange Server. Many businesses use MS Outlook and MS Exchange Server to access email and to provide calendaring, notes, file sharing, and other collaborative functions. General industry complaints about Exchange Server center around scalability, administration (backup and restore in particular), and licensing fees.

A drop-in alternative needs to have compatibility with MS Outlook because it's intended to replace Exchange Server in an environment in which there are Microsoft desktops in existence using Outlook. A work-alike alternative provides similar features to Exchange Server, but does not offer compatibility with the MS Outlook client itself; this incompatibility with Outlook is typical of many of the open source alternatives.

Several drop-in alternatives exist, none of which is fully open source because some type of proprietary connector is needed to provide the services to MS Outlook clients (or provide Exchange services to the Linux Evolution client). For Outlook compatibility, the key seems to be the realization of a full, open implementation of MAPI , Microsoft's Messaging Application Program Interface . That goal is going to be difficult to achieve because MAPI is a poorly documented Microsoft protocol. For Linux-only solutions, the missing ingredient for many alternatives is a useable group calendaring/scheduling system similar in function to that provided by Exchange Server/Outlook.

Of course, independent applications for these functions abound in the open source world, but one characteristic of groupware is its central administration; another is that all components can share information.

The following sections examine several of the available servers, beginning with MS Exchange Server itself and moving toward those applications that have increasing incompatibility with it. None of these servers are provided with Fedora.

Exchange Server and Outlook seem to be the industry benchmark because of their wide spread deployment. They offer a proprietary server providing email, contacts, scheduling, public folders, task lists, journaling, and notes using MS Outlook as the client and MAPI as the API. If you consider what MS Exchange offers as the full set of features, no other replacement offers 100% of the features exactly as provided by MS Exchange Server — even those considered drop-in replacements. The home page for the Microsoft Exchange Server is http://www.microsoft.com/exchange/.

CommuniGate Pro is a proprietary, drop-in alternative to MS Exchange Server, providing, email, webmail, LDAP directories, a web server, file server, contacts, calendaring (third-party), and a list server. The CommuniGate Pro MAPI Connector provides access to the server from MS Outlook and other MAPI-enabled clients. The home page for this server is http://www.stalker.com/.

Oracle Collaboration Suite, or OCS as it is known, is a proprietary application that supports deployment on Linux. It provides a number of services, including email (both POP and IMAP based), file sharing, calendaring, and instant messaging to name but a few. You can find it at http://www.oracle.com/collabsuite/.

The Open Xchange message server is based on Cyrus-imap and Postfix. Most of the server's groupware features are provided by a proprietary web-based groupware server (ComFire). Open Xchange also uses Apache, OpenLDAP, and Samba to provide public directories, notes, webmail, scheduler, tasks, project management, document management, forums, and bookmarks. Some compatibility with MS Outlook is provided. The home page is http://www.open-xchange.org/.