Section C.5. Open Source Email Client Solutions

C.5. Open Source Email Client Solutions

Solutions in the email client space tend to be single-purpose applications that help the user read, send, and manage email as well as manage their address books. Microsoft Outlook is the commercial market leader in this space, as it is used on more than 60% of corporate desktops. Historically, these applications tended to be islands unto themselves, but now most are moving toward supporting external mail-related standards as they mature. For instance, LDAP is supported for address books, and the PGP, GPG, SSL, and TLS standards are supported for security.

C.5.1. Open Source Email Client Capabilities

All decent email clients should support the ability to read, send, and manage email. Features to sort the collection of messages by time and sender are also expected. Email clients should also allow users to easily manage their address books, at a bare minimum.

The state-of-the-art email clients, meanwhile, are expected to handle HTML mail and to thread together group messages related to a single conversation. The current trend is to improve search features that can quickly search across a large mailbox, as well as to provide dynamic filtering criteria that are kept up-to-date as new messages arrive. Another option to look for is support for virtual folders. Virtual folders allow the user to view messages in one folder that are located in several other folders, based on a search criterion. Novell Evolution provides support for virtual folders. Email views are another advanced feature that can be used to manage email. Views are search filters that are applied dynamically. One of this book's authors uses a TODO label and the TODO view to effectively use Mozilla Thunderbird as a mini personal information manager. Some email readers, such as Microsoft Outlook and Novell Evolution, feature built-in calendaring, but most email applications do not.

The ability to manage multiple email identities in one email reader is of extreme value these days. This allows a user to respond to a personal message that was accidentally sent to a work address from a personal address and continue the conversation there. Related to this is the ability to control the reply-to header, which allows the user to redirect responses to the email at a separate address. The ability to search across multiple email accounts is another useful feature.

Here is a detailed categorized listing of the most useful features of an email client. Microsoft Outlook 2003 supports these features, although its quality of implementation varies.

• Effective layout that doesn't confuse the novice user and doesn't limit the power user, including:

  • Support for two- and three-pane layouts

  • The ability to display and group messages via a variety of criteria, including sender, date, conversations (or threads), and topic (or subject)

  • The ability to mark or flag messages for later action, and to create custom flags

• Search capability that should include the ability to:

  • Search headers for senders, recipients, or subjects within a specified date range

  • Search the body of email text

  • Search across all message attributes or across certain headers

• Integrated address book support with:

  • A built-in address book

  • Auto completion of email addresses while composing email

  • Support for corporate address books via LDAP and Active Directory

  • Automatic building of an address book via regular use of the email client

• Integrated spelling support with:

  • A built-in spellchecker or use of spellchecking services provided by the operating system

  • The ability to spell as you type

• Content scanner support including:

  • Integration with client-side content scanners such as ClamWin and SpamBayes

  • Support for server-side content scanners such as Clam AntiVirus and SpamAssassin

• Security and encryption support with:

  • Support for transport layer security mechanisms such as SSL and TLS

  • Support for message content security with mechanisms such as S/MIME, PGP, and GPG

C.5.2. Open Source Email Client Projects

Open source email client projects are finally starting to target the Windows platform and provide fixes for Microsoft Outlook's security vulnerabilities.

Email applications in commercial projects, such as Microsoft Outlook, tend to be a collection of related groupware functions: shared address books and calendars, journals, and other personal information management functions. However, their open source counterpartsNovell Evolution and KMail being two primary examplesare closing the gap and building a strong business case for an enterprise to standardize on them. There is also the promise of Chandler. Chandler is the next-generation personal information manager, designed by Mitch Kapor of Lotus Agenda fame. Being developed from scratch, Chandler uses email as the central application for messaging and collaboration and provides usage scenarios that are very different from the current standard (which is based largely on Outlook). Chandler is currently in pre-alpha stage, with no definite release date for Version 1.0, but due to its extraordinary promise, it is worth keeping an eye on.

We recommend some open source email clients for the most common enterprise usage scenarios. Novell Evolution is the current best bet for replacing an enterprise-grade client such as Microsoft Outlook. Mozilla Thunderbird is the best of the low-end clients and is a very suitable replacement for Outlook Express. Mutt is a text console-based client that is perfect for extended messaging needs in datacenter environments where an IT person might need to use mail but feels hampered by the default Unix mail client.

C.5.3. Novell Evolution

Novell's Evolution is a truly enterprise-ready email client. It is also a functional personal information manager. It has all the basic email reader functions and several advanced email functions not found in the competition or not nearly as well implemented. It has good support for enterprise email platforms, including Microsoft Exchange and Novell GroupWise, with better support expected in the next major release. This email client should be on every IT manager's short list of open source email clients.

C.5.3.1 Product strengths

• Several advanced features are well implemented (virtual folders, powerful search, etc.).

• It features Exchange connectivity.

C.5.3.2 Product weaknesses

• Performance is lagging.

• The Exchange connector is not yet open source.

C.5.4. Mozilla Thunderbird

Mozilla Thunderbird is a powerful and speedy email client that is great for home use and is ready for enterprise use, depending on the email server deployed. It provides excellent support for POP, good support for IMAP, and partial support for Microsoft Exchange via IMAP and LDAP, but it still lacks the smooth integrated corporate email experience for the enterprise that Microsoft Outlook provides. Thunderbird 1.0 was recently released after a long and stable beta-testing period. It continues to mature and enhance at a rapid pace, with several useful extensions also in the process of being released. It is well worth keeping an eye on.

C.5.4.1 Product strengths

• It has robust support for basic email client features.

• Several advanced features (threads, labels, search folders) provide a very customizable email workflow experience.

• It is very extensible; several useful extensions are already available.

• It integrates well with Mozilla Firefox and Sunbird.

• It features integrated support for other content syndication formats such as RSS.

C.5.4.2 Product weakness

• Message template support is less than mature.